【推荐1】数组a中存储着全校学生的学号和BMI信息，格式为[['0101',19.2],['0102',18.5],['0103',20.1],...]。其中每条数据的第一项为学号，第二项为BMI值。数组a已经按学号升序排序，现要求按照BMI值进行降序排序，BMI相同情况下仍然按照学号保持升序。则下列程序段可以实现该功能的是（     ）

A．for i in range(1,n):             for j in range(n-i):                       if a[j+1] > a[j]:                             a[j], a[j+1] = a[j+1], a[j]

B．for i in range(1,n):                for j in range(n-i):                          if a[j][1] > a[j+1][1]:                                     a[j], a[j+1] = a[j+1], a[j]

C．for i in range(1, n):               for j in range(n-1, i-1, -1):                         if a[j][1] <= a[j-1][1]:                                a[j], a[j-1] = a[j-1], a[j]

D．for i in range(1, n):               for j in range(n-1, i-1, -1):                        if a[j][1] > a[j-1][1]:                                    a[j], a[j-1] = a[j-1], a[j]

【推荐2】有如下Python程序段
def shift(s,flag):
       if len(s)==1:
             return s
       elif s[0] in ".?!":
             return s[0]+shift(s[1:],True)
       elif flag:
             return s[0].upper()+shift(s[1:],False)
             #upper()把字符串s 中的小写字母转换成大写字母
       else:
             return s[0]+shift(s[1:],False)
print(shift("which is strong!basic，java or python?",True))
运行上述程序段后，输出的结果是（     ）

A．Which is strong!Basic，Java or python?	B．Which Is Strong!Basic，Java Or Python?
C．Which is strong!Basic，java or python?	D．WHICH IS STRONG!BASIC，JAVA OR PYTHON?