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)
①The  of this mountain is 5540 meters. (高度)
②If you want to come, please let us know as soon as  (可能的).
③There are  of people by the sea. (千)
④The more careful you are, the fewer   you'll make. (错误)
⑤Mum is always busy. Last week she   three meetings. (出席)
⑥This piece of advice is very . I'll take it. (use).
⑦Bad weather sometimes causes  (nature) disasters.
⑧ , I could get the last plane ticket to the USA. (luck)
⑨The twin brothers like keeping secrets to  . (they)
⑩The radio says it will be much (rain) tomorrow.