2 . During the trial, the prosecution was accused of withholding c________ evidence from the defence. (根据首字母单词拼写)

3 . The turning point in her political career came when she was chosen to fight a c________ by-election. (根据首字母单词拼写)

4 . Price will be a c________ factor in the success of this new product. (根据首字母单词拼写)

5 . It is c________ that the problem is tackled immediately. (根据首字母单词拼写)

6 . Her work has been c________ to the project's success. (根据首字母单词拼写)

7 . Hubble observations have played a c________ role in the discovery of the mysterious dark energy. (根据首字母单词拼写)

8 . It is clear that telescopes are c________ tools for space exploration. (根据首字母单词拼写)

9 . Seeking and accepting constructive feedback (反馈) is ____ (关键的) to growth. （根据汉语提示单词拼写）

10 . Certainly, these early learning years are c______ (至关重要、关键) to a child’s educational development. (根据中英文提示填空)