The way of life he was used to _______ when he came to study in America.

A．change

B．changed

C．changing

D．being changed

从洋葱表皮上撕下一小块透明薄膜制成玻片标本用来临时观察，这种玻片标本称作（　　）

A．切片

B．永久装片

C．涂片

D．临时装片