图为家蚕发育的全过程，请写出他的正确顺序（   ）

A．①③②④

B．④③②①

C．①②④③

D．④①②③

根据中文提示，完成对话

A: Hello.

B: Hello.     1   (可以)I speak to Mr. Smith?

A: I'm sorry ,he's on the other line. Who's calling?

B: __2   (我)is Mr. Brown, his colleague.

A: Would you hold on a while or may I take a _ 3   (口信)?

B: I'll call him__4   (稍后)，thank you. Coodbye .

A: Goodbye.