0.25 mol A的质量是16 g，A的相对分子质量（或相对原子质量）是（

从下面的方框中选择适当的选项补全对话。（有两项是多余的）

A: I don’t think I can finish all of that. B: Did you enjoy the play? C: Who is that? D: Oh, that’s too bad. E: Let me tell you. F: This is Bob. G: What about math?

(Bob is ill. He is phoning Ann for the school work.)
Ann: Hello.  
Bob: Hello. __小题1:__
Ann: Hi, Bob. How are you feeling today?
Bob: Oh, I’m fine now. Can you tell me what happened in our class?
Ann: Sure. __小题2:__, oh, yes. In history class we finished talking about World War II . We have to study Unit 7 and Unit 8 for an exam tomorrow.
Bob: __小题3:__I didn’t read Unit 8 yet. What did you do in English?
Ann: Not much. We worked on a play in groups. We don’t have any homework.
Bob: __小题4:__
Ann: We have a lot of math homework. We have to do the problems on page 17, 18, 19 and 20.
Bob: Oh, dear! __小题5:__ Maybe I can be ill tomorrow too.