NEW STRAINS OF VIRUSES ARE TRANSMITTED TO MAN BY __________A. A VAR...

4. - 2 DE THI THU DH MON THI TIENG ANH VA DAP AN
Tiếng Anh 2 DE THI THU DH MON THI TIENG ANH VA DAP AN

4. New strains of viruses are transmitted to man by __________

A. a variety of means. B. diseased lower animals.

C. a group of migrating birds. D. a type of wild pig.