Which of the following is NOT given as an advantag...

C

- Hướng dẫn giải

Phương pháp giải:

Giải chi tiết:

Đáp án C

Thông tin ở đoạn cuối cùng:

- The biological agents now in use are environmentally benign and are harmless to humans. (They are safer for workers)

- leave crops and other plants untouched.( They are less likely to destroy desirable plants.)

- Furthermore, a number of biological agents can be administered only once, after which no added applications are needed. (They do not have to be used as often.)