根据句子意思，用括号中所给汉语提示或英语单词的适当形式填空。(每空一词)

小题1:The __________ of this mountain is 5540 meters. (高度)

小题2:If you want to come, please let us know as soon as ____________(可能的).

小题3:There are __________ of people by the sea. (千)

小题4:The more careful you are, the fewer ____________ you’ll make. (错误)

小题5:Mum is always busy. Last week she __________ three meetings. (出席)

小题6:This piece of advice is very __________. I’ll take it. (use).

小题7:Bad weather sometimes causes ___________ (nature) disasters.

小题8:____________, I could get the last plane ticket to the USA. (luck)

小题9:The twin brothers like keeping secrets to ____________. (they)

小题10:The radio says it will be much ____________ (rain) tomorrow.

关于力的叙述，正确的是（　　）

A．一个物体能发生力的作用

B．物体间力的作用是相互的

C．两个物体必须互相接触才能发生力的作用

D．力的单位是千克