在拧螺丝钉时,螺纹____的螺丝钉比螺纹____的螺丝钉更省力。
Dad , why should I stop ____ computer games ? For your health , my boy , I'm afraid you _______ .
I am going to make supper now. _________ there any mutton and tomatoes in the fridge?
10mL水与10mL酒精混合,所得液体体积小于20mL,这一现象主要说明( )