下图所示人体血液循环，图中①②③④表示心脏各腔。
（1）体循环的途径是②__________→C___________→E组织器官→D下腔静脉→③右心房→④右心室。
（2）血液从A端流到B端后，由于经过了肺部的气体交换，血液由___________变成了动脉血。
（1）左心室、主动脉
（2）静脉血
1是左心房，2是左心室，3是右心房，4是右心室，C是与左心室相连的主动脉，在肺部毛细血管处，肺泡将氧气给了血液，血液将二氧化碳给了肺泡，所以血液从A端流到B端后，血液由静脉血变成动脉血。
| 完形填空。 | |||
| I have a good friend. __1__ name is Mary. She__2__ from America. She is __3__ China with her father and mother. She can__4__ a little Chinese. She is in the No. 15 Middle School in Shanghai. Her father and mother __5__ . They are in the No. 50 Middle School. Mary is a good student. She __6__ school five days a week. She __7__ up early. She __8__ to be late. She often goes to school very early. But today she got up late. So she got to the classroom at seven thirty. __9__ there weren't any students in the classroom. She wasn't late. She was still early. It was Saturday today. The students were all __10__ . (New words: got是get的过去式 was是is的过去式 were是are的过去式) | |||
| ( )1. A. She ( )2. A. come ( )3. A. at ( )4. A. say ( )5. A. is teacher ( )6. A. is go ( )7. A. like getting ( )8. A. like ( )9. A. And ( )10. A. at home | B. He B. comes B. in B. tell B. are teachers B. is B. likes getting B. likes B. But B. in home | C. Her C. are C. of C. talk C. is doctor C. go to C. like get C. don't like C. So C. at school | D. His D. go D. from D. speak D. are doctors D. goes to D. likes get D. doesn't like D. Too D. in school |