下列有关我国各民族的地区分布状况的描述，正确的是（  ）

体育课后腿部和手部肌肉酸痛是因为肌肉中积累了（　　）

根据所给情景完成下列对话，每空一词。

A: Hi! Jack. Do you want to (1) ____ English with me?

B: Yes, I (2) ____ .

A: What (3) ____do you often go to school?

B: I often go to school (4) ____  seven o'clock.

A: Oh, it's quite early. I get (5)____at seven. I often go to school at 7:30.

B: My home (6) ____  near the school. Do you have lunch (7) ____ home?

A: No, I (8) ____ . I have lunch at school. After lunch I play basketball (9) ____my friends.

B: Great! I like playing basketball, (10) ____ . But I play it at 4:30 in the afternoon.