1. Although insects are harmful to plants, their existence contributes a great part to____which helps to make a balanced environment
A. Biology
B. Biophysics
C. Biosphere
D. Biodiversity
2. ____a vacation now if she had more time?
A. Will she take
B. Would she take
C. Is she taking
D. Does she take
3. _____yet?
A. Was the report written
B. Has the report written
C. Did the report write
D. Has the report been written