用于主动免疫的是A.抗毒素B.减毒疫苗C.IFN-aD.造血干细胞移植E.免疫抑制剂

All the following sentences definitely indicate the perfect tense EXCEPT______.

A．I shouldn"t have been to school for today is the weekend

B．I have never thought that my work could be accepted

C．I had left this place when my father lost his job

D．I have seldom heard from my sister and this is what I concern most

请帮忙给出正确答案和分析，谢谢！

可用于判断18岁以上个体超重的指标是

A.肺活量指数

B.握力指数

C.BMI指数

D.身高坐高指数

E.身高体重指数

请帮忙给出正确答案和分析，谢谢！

反映机体肺通气能力的指标是

A.肺活量指数

B.握力指数

C.BMI指数

D.身高坐高指数

E.身高体重指数

请帮忙给出正确答案和分析，谢谢！

They encourage doctors to______cheaper generic drugs instead of more expensive brand names.

A．recommend

B．advocate

C．specify

D．prescribe

请帮忙给出正确答案和分析，谢谢！

The Central Bank is busy with estimating the circulation of its currency in the economy. The underlined part means

A．rotation

B．reserve

C．volume

D．cycling

请帮忙给出正确答案和分析，谢谢！