学校改建时,工人师傅用透明塑料管检查窗台是否水平,当管中的水静止时,管两端的水面一定____,当塑料管的一端抬高10cm,最终两端水面的高度差为____。
This is a farm.It is____and warm today.I can see a____and her three children,three____,two____,a____and a____on the farm.There is a____on the left.Behind the farm there are three high____.In the sky there are____and ____.
关于电路中电源的认识,下列说法正确的是( )