Dragon Boat Festival is my favourite festival.(对划线部分提问)
____ is ____favourite festival ?
—Last night I worked until 1 o'clock. And ____ made me sick. The boss asked me to have a rest.
轮船在12m深的河里航行,船底距河底8m.若船底有一个面积4cm2的小洞,用塞子堵住,塞子受水的压力为多大?g=10N/kg
最先证明地球是个球体的事件是( )