1 . “南澳牡蛎”是我国地理标志产品,产量高、肉质肥、营养好,素有“海洋牛奶精品”的美誉.2024年该基地考虑增加人工投入,现有以往的人工投入增量x(人)与年收益增量y(万元)的数据如下:
该基地为了预测人工投入增量为16人时的年收益增量,建立了y与x的两个回归模型:
模型①:由最小二乘公式可求得y与x的线性回归方程:
;
模型②:由散点图的样本点分布,可以认为样本点集中在曲线:
的附近,对人工投入增量x做变换,令
,则
,且有
,
,
,
.
(ii)根据下列表格中的数据,比较两种模型的决定系数
,并选择拟合精度更高、更可靠的模型,预测人工投入增量为16人时的年收益增量.
(2)根据养殖规模与以往的养殖经验,产自某南澳牡蛎养殖基地的单个“南澳牡蛎”质量(克)在正常环境下服从正态分布
.购买10只该基地的“南澳牡蛎”,会买到质量小于20g的牡蛎的可能性有多大?
附:若随机变量
,则
,
;
样本
的最小二乘估计公式为:
,
,
.
人工投入增量x(人) | 2 | 3 | 4 | 6 | 8 | 10 | 13 |
年收益增量y(万元) | 13 | 22 | 31 | 42 | 50 | 56 | 58 |
模型①:由最小二乘公式可求得y与x的线性回归方程:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/84bc4486ffeb321242a9982309efff8c.png)
模型②:由散点图的样本点分布,可以认为样本点集中在曲线:
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b328c19977481e5ea0ca585af1ef4394.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d40b90ca3b73b0040365d9f55be51433.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a8ee45ed2358f5d5ad60eaf4c8830da.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4c3af5d6a45c01b7d0c7c537506e1c56.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f9c4fac1fe3facd6cec349abafe3ae59.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dd1aec923d21f9cdf93c257769eca972.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/79728a92965ea4df0a12de9878245297.png)
(ii)根据下列表格中的数据,比较两种模型的决定系数
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4c85067c53e936ef32da818efe04bdbb.png)
回归模型 | 模型① | 模型② |
回归方程 | ![]() | ![]() |
![]() | 182.4 | 79.2 |
(2)根据养殖规模与以往的养殖经验,产自某南澳牡蛎养殖基地的单个“南澳牡蛎”质量(克)在正常环境下服从正态分布
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5b855415af8163cef49c0706e3c0528b.png)
附:若随机变量
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/e188b5f28f5dc86364cb18c11f8d4702.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/94c741455594dbc5293c436d8d2c0275.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8eabdfcbc03a1d0b223555af8dbf4315.png)
样本
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/539241dbd325e8aef033e0a89ff60125.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/853e9ba2d135b2d324679c0f4110149a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7ebff20f21ae41fd8d1f1e3145895842.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1f763c9590d5ca681acf466e4c6d7fa2.png)
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2 . 请在①
,②
,
③
三个条件中选择一个,补充在下面的问题中,
所对的边分别是
,已知_____.
(1)求角
;
(2)若
,点
在边
上,
为
的平分线
,求边长
的值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c55c2d6765572a01f646a8fcf1b660ee.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/28b6e8a8f6a82b3d5510066a0eae566b.png)
③
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0867d4b6c3d1cc771e5e83974ca111ca.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ab609a6574633ebabcff3e73fa862081.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/76f0649064a085fb74c997fb507a9b6d.png)
(1)求角
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3320a13248a3a1208ff6ee85c9d26f36.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9d78abbad68bbbf12af10cd40ef4c353.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8fabb884dc5f9609de491245463bbe9a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/18483c9c195ecd922772527fa85c0fcb.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0a6936d370d6a238a608ca56f87198de.png)
您最近一年使用:0次
名校
解题方法
3 . 记
.
(1)若
,求
和
;
(2)若
,求证:对于任意
,都有
,且存在
,使得
.
(3)已知定义在
上
有最小值,求证“
是偶函数”的充要条件是“对于任意正实数
,均有
.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7d80225e12934cd8d4ffc73d5fad815d.png)
(1)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/04beea76c59a6c5b096d8c5a3b77f8a9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8e1b9f62690647a1597f4000ad5a64b9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a4c8381377b90826897eb4bf16cb3bae.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/28034dcafe542a98d95d4504ad7d8a3e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/22dd8b3dc4c609bab82d356a5cc2208d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4def7108b0a2338f07a0143b00b48271.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0a6936d370d6a238a608ca56f87198de.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3761d7ab4d00c91177fdbde67af36089.png)
(3)已知定义在
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a43b2faa4f81f32d94612dce724e772b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/09f86f37ec8e15846bd731ab4fcdbacd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/09f86f37ec8e15846bd731ab4fcdbacd.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/071a7e733d466949ac935b4b8ee8d183.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/625e9d3c298a595678933b59583632c2.png)
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4 . 如图所示的几何体是由等高的直三棱柱和半个圆柱组合而成,
为半个圆柱上底面的直径,
,
,点
,
分别为
,
的中点,点
为
的中点.
![](https://img.xkw.com/dksih/QBM/2024/5/31/3508518211018752/3520553871540224/STEM/24a32289908a4049b65c769f665382cb.png?resizew=222)
(1)证明:平面
平面
;
(2)若
是线段
上一个动点,当
时,求直线
与平面
所成角的正弦值的最大值.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/56f7ba05c54b3de1f4378f7c8eb58328.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ed10df4140819d5451773a45de66201b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/209acf15985d1ea1ad86fc4a37e38c0b.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/a0ed1ec316bc54c37c4286c208f55667.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/60ef95894ceebaf236170e8832dcf7e3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8455657dde27aabe6adb7b188e031c11.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cd8d7a1d7df296227f18a816805bf868.png)
![](https://img.xkw.com/dksih/QBM/2024/5/31/3508518211018752/3520553871540224/STEM/24a32289908a4049b65c769f665382cb.png?resizew=222)
(1)证明:平面
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c9fc224dae99dd34e997eaaa1973edb9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7bff3ccea5989c60e51e321af3f53f54.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/456175ea34492f0bc025aaab668fa659.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/462b1c65b1b233ab98a90c164c0968c7.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7d0ff310aabd2282b539537ebed3f788.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/ca67a5b8f69507c8b80379e86f90a8ce.png)
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5 . 在平面内,若直线
将多边形分为两部分,多边形在
两侧的顶点到直线
的距离之和相等,则称
为多边形的一条“等线”,已知
为坐标原点,双曲线
的左、右焦点分别为
的离心率为2,点
为
右支上一动点,直线
与曲线
相切于点
,且与
的渐近线交于
两点,当
轴时,直线
为
的等线.
(1)求
的方程;
(2)若
是四边形
的等线,求四边形
的面积;
(3)设
,点
的轨迹为曲线
,证明:
在点
处的切线
为
的等线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0f85fca60a11e1af2bf50138d0e3fe62.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0f85fca60a11e1af2bf50138d0e3fe62.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0f85fca60a11e1af2bf50138d0e3fe62.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0f85fca60a11e1af2bf50138d0e3fe62.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/96c4088276acdbede4781b2ebc466366.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b90ff138a12d957605d7633d4633e1f5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/294f5ba74cdf695fc9a8a8e52f421328.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dad2a36927223bd70f426ba06aea4b45.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/01c74a907dda6bb7d9d56d009d9df253.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0803835d6f594a60bd16c823e3ad2cd6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c50866229ec5a3640fb250f9bd2192b3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/33d776753746914c2410a3946c357f35.png)
(1)求
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2a30f3a8b673cc28bd90c50cf1a35281.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b2bdeeb6f5e38e3464c357d00839a6ce.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dfffd420523729074995e9e55f464d4c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/dfffd420523729074995e9e55f464d4c.png)
(3)设
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d7bfffabff7859a44122f496c9e4c654.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/895dc3dc3a6606ff487a4c4863e18509.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4bcd8ee2d8367c167d6ae0abc741b6b8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/4bcd8ee2d8367c167d6ae0abc741b6b8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/895dc3dc3a6606ff487a4c4863e18509.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b2cfd997d3b66a3b8f7731b26f0ab0c8.png)
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名校
解题方法
6 . 已知正项等差数列
的公差为2,前
项和为
,且
成等比数列.
(1)求数列
的通项公式
;
(2)若
求数列
的前
项和.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b6a24198bd04c29321ae5dc5a28fe421.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/08eb71ecf8d733b6932f4680874dbbf3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b91c13eaedd3a65b08e71d33a7a7c7a2.png)
(1)求数列
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83cf38189d5cbf627d2b82ac0eb76006.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/96abfe2da27a63e6affb19a0c80236d9.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8f05b1997d02b7483b7ece61061faba1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/034ba25825c13725931c483aa47c9363.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1b17a9b9bb8bf6bb9865e37f204da5c5.png)
您最近一年使用:0次
7 . 某高校为了提升学校餐厅的服务水平, 组织4000名师生对学校餐厅满意度进行评分 调查,按照分层抽样方法,抽取200位师生的评分(满分100 分)作为样本,绘制如图所示的 频率分布直方图,并将分数从低到高分为四个等级:
的值,并估计满意度评分的
分位数;
(2)若样本中男性师生比为
,且男教师评分为80分 以上的概率为0.8, 男学生评分为80分以上的概率0.55, 现 从男性师生中随机抽取一人, 其评分为80分以上的概率为多少?
(3)设在样本中,学生、教师的人数分别为
,记所有学生的评 分为
,其平均数为
,方差为
,所有教师的评分为
,其平均数为
,方差为
,总样本的平均数为
,方差为
,若
,试求
的最小值.
满意度评分 |
| |||
满意度等级 | 不满意 | 基本满意 | 满意 | 非常满意 |
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0a6936d370d6a238a608ca56f87198de.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/267c88e52743f3dedd4e60569cb958fe.png)
(2)若样本中男性师生比为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/fa9c934d84feba963335cc7edf01610e.png)
(3)设在样本中,学生、教师的人数分别为
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cb785c57f06f8e0051e49a5f1b43fde1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1402b0375d6babc0b979a368d1fbb54e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/bfbe7f95b5d89f9409ec24536da9e826.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/8a63cadbf6b0d54955a3c3d1b7a62b14.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/35ba484662ddaac29c2c44ed136f79c6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/eb525270c748eddaaecc4a549cca250e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/9289410bd35c9d57326b93cc7f4c4767.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/d41042207515dd2e8349c805e6aee400.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/671f43c79d612c93a6d160335e86e177.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/3d954d1e6b433661e694eddc231be784.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/294f5ba74cdf695fc9a8a8e52f421328.png)
您最近一年使用:0次
解题方法
8 . 已知
为坐标原点,曲线
在点
处的切线与曲线
在点
处的切线平行,且两切线间的距离为
,其中
.
(1)求实数
的值;
(2)若点
分别在曲线
上,求
与
之和的最大值;
(3)若点
在曲线
上,点
在曲线
上,四边形
为正方形,其面积为
,证明: ![](https://staticzujuan.xkw.com/quesimg/Upload/formula/634eecef5979fe32878d032e9736bcad.png)
附:ln2 ≈ 0.693.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1dde8112e8eb968fd042418dd632759e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/325cb5d7a2edc99c9bfcf39e6ffc7c5c.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/248b75c2ba3d6f870b1a7255e652b8b4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/b037b9629c12214eb24d990fc9855852.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/addc3241a83f4b61d46402319b7f1da1.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cf298f00799cbf34b4db26f5f63af92f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c90e8d5d7fed033f48270b1ff825fcd5.png)
(1)求实数
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/62ff2912fd8d93b6e692936d95b727c5.png)
(2)若点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6f44755c5fee4b90266eac73ad47a128.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/32595168b1cc7fd374aeb8d833c1cbb8.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/579d861f3f214342af735e6f0a8db139.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/2d3ea1f0e09c8f73a18a08f14188f264.png)
(3)若点
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/0ae6f48b9a53c0155a692509cf31f7e6.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/942c2141d01bde6b48210c56a17fc75e.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5aa69fd8445d01c98634c2e885b47d5a.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/1938c093dd2fbcb752d0eb7a18d143b2.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/411b38a18046fea8e9fab1f9f9b80a5f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/cf231f8f86fb922df4ca0c87f044cec3.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/634eecef5979fe32878d032e9736bcad.png)
附:ln2 ≈ 0.693.
您最近一年使用:0次
9 . 已知双曲线
的左、右焦点分别为
,点
在双曲线
上,且直线
的倾斜角是直线
的倾斜角的2倍.
(1)求双曲线
的标准方程;
(2)若
,
是双曲线
上的两个动点,且恒有
,是否存在定圆与直线
相切?若存在,求出定圆的方程,若不存在,请说明理由.
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/83bf4fd84818abac17a9d21237ac5ce5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/40f98254a6193566587a70c7d95fdabf.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/786ab40492d54c5a17fd385df50f0de4.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/183b6a0cef4256c9696a5bca31053da5.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/6b67528f875a6d4bac8bbf784f7b66a0.png)
(1)求双曲线
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
(2)若
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/5963abe8f421bd99a2aaa94831a951e9.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/7f9e8449aad35c5d840a3395ea86df6d.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/c5db41a1f31d6baee7c69990811edb9f.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f788fb0059b7356dc6c7811f46057e66.png)
![](https://staticzujuan.xkw.com/quesimg/Upload/formula/f52a58fbaf4fea03567e88a9f0f6e37e.png)
您最近一年使用:0次