Question

As many as 100 species of fish, some ____ to these waters, may have been affected by the pollution．

1. A.
   relevant
2. B.
   immune
3. C.
   unique
4. D.
   convenient

Answer 1

C
试题分析：考查单词意思, relevant意思“有关的”， immune意思“免疫的”， unique意思“唯一的”，convenient意思“方便的”，句子意思“多达100种鱼，一些与对于这些水来说是唯一的，可能被污染影响了”，所以选C
考点：考查单词意思
点评：固定词组be unique to sth意思“对于某物是独一无二的”， may have been done意思“对做过事情的不肯定推测” ，must have done意思“对过去的肯定推测”。