在一定温度下，反应A₂（g）+B₂（g）  2AB（g）达到反应限度的标志是

A、容器内气体的总压强不随时间变化而变化

B、A₂、B₂和AB的物质的量不再改变

C、c（A₂）：c（B₂）：c（AB）===1：1：2

D、A₂和B₂的物质的量之和与AB的物质的量相等

问答配对（10分）

小题1:How old is John?                      A  Yes, please.

小题2:Where is the school?                   B  Yes, I am.

小题3:What is the last day of the week?         C  He is from America.

小题4:What does your father do?              D  He is a policeman.

小题5:What do you want to be?               E  It’s on Park street .

小题6:Is your mother a teacher?               F  Saturday.

小题7:How’s it going?                      G  Not bad.

小题8:Where is Mr. brown from?              H  Yes, she is.

小题9:Can I help you?                       I  A doctor.

小题10:Are you late for school today?           J   He is ten years old.