作为中学生，我们应该如何做才有利于保护生物圈？

青岛房屋内的光照面积S最大时，地球公转的位置大致位于(      )

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.