AIDSissaid的精选

问题详情： AIDSissaid______thebiggesthealthchallengetohumanoverthepastfewyears.A.thatitis    B.tobe               C.thatithasbeen  D.tohavebeen【回答】D知识点：非谓语动词题型：选择题...

问题详情：AIDSissaid__________thebiggesthealthchallengetobothmenandwomeninthatareaoverthepastfewyears. A．thatitis       B．tobe          C．thatithasbeen   D．tohavebeen【回答】D知识点：不定...