1 . The old man was able to provide the police with some __________ (有价值的) information.

2 . John is a doctor, so he is an ______ (受过教育的) person．

3 . He frequently did _______ (自愿的) work during his spare time at university. (根据汉语提示单词拼写)

4 . Many of the species ______ (原产于) to California, such as the prickly chaparral, rely on fires to multiply. （根据汉语提示单词拼写）

5 . With the English teacher’s support, he thought senior high was easy and felt c______（自信的）about his future. （根据中英文提示单词拼写）

7 . Good teamwork and communication are __________ (强有力的) tools for success. (根据汉语提示单词拼写)

8 . The talks will focus on ________ ( 经济的 ) development of the region.(根据汉语提示单词拼写)

9 . Your work has shown a ____________ (有重大意义的) improvement. (根据汉语提示单词拼写)

10 . He is a ____________ (频繁的) visitor to the art exhibitions. (根据汉语提示单词拼写)