### Chinese: 护林员会密切监督参加虫害防治补充试验的射手，因为试验会受到监测，并会评估其效果。
### English: Rangers closely monitor shooters participating in supplemental pest control trials as the trials are monitored and their effectiveness assessed.
### Errors: There is a critical change of gender pronoun error in the English translation.

### Improved English: Rangers closely monitor shooters participating in supplemental pest control trials as the trials are monitored and their effectiveness assessed.
