It was the A/N1H1 epidemic ____ spread almost throughout the country ____ promoted the research and production of the flu vaccine.
A.that…that | B.that…which | C.what…that | D.that…what |
推荐套卷
It was the A/N1H1 epidemic ____ spread almost throughout the country ____ promoted the research and production of the flu vaccine.
A.that…that | B.that…which | C.what…that | D.that…what |