细线下挂一个质量为m的小球,现用一个力F拉小球使悬线偏离竖直方向θ角处于静止状态,如图所示,则拉力F的最小值为___________。
Fsinθ
句型转换。
1. He'd like some beef for dinner. (变为同义句)
He ________ some beef for dinner.
2. They would like chicken and cabbage noodles. (就画线部分提问)
________ ________ ________ noodles would they like?
3. Jim wears Size M. (就画线部分提问)
________ ________ ________ Jim wear?
4. He'd like a cup of green tea. (就画线部分提问)
________ ________ he ________ ?
5. The bowl of noodles has mutton and tomatoes in it. (变为同义句)
This is a bowl of noodles ________ mutton and tomatoes ________ it.
向下图试管里的水中加入下述某种物质后,原来U型管内在同一水平上的红墨水,右边液面降低了些,左边液面上升了些,则加入的物质是 ( )
A.硝酸铵
B.生石灰
C.活性炭
D.烧碱