A:0.5元货币购买力
B:1元货币购买力
C:2元货币购买力
D:4元货币购买力
⑴You need a swimming cap. ____
⑵First,you should wash yourself. ____
⑶Next,you should do warm-up exercises. ____
⑷Then, you can enjoy your swimming lessons. ____
⑸You need a swimsuit.____
A. B. C. D. E.
“天下为家”取代“天下为公”开始于( )
人体中红细胞的直径约为0.0000077m,将数0.0000077用科学记数法表示为( )
在下列条件中,不能判定两直角三角形全等的是( )