异面体的类型包括()
A.立方体
B.四面体
C.八面体
D.十二面体
E.星形多面体
参考答案:A, B, C, D, E
用适当的介词填空。
1. Daming invites Tony ______ the cinema.
2. I often go shopping ______ my mother.
3. The piano lesson is ______ Sunday afternoon.
4. We have four classes ______ the morning.
5. We see The Lion King ______ New Times Cinema.
用图所示装置演示“静摩擦力”的大小,当重物连同盘的总重力为2N时,弹簧测力计示数为8N.现在盘中加钩码,当盘与钩码总重力为12 N时,弹簧测力计示数为
A.12N
B.8N
C.4N
D.20N