根据英语解释写出相应的单词
问题描述：
根据英语解释写出相应的单词
Someone who studies or works in biology .the force that cause something to fall to the ground or to be attracted to another planet .the typical weather conditions in a partieulcs area .very difficult to believe and therefore probably untrue .a thin paper cover in which you put and send a letter 共五句五个单词
答
No.1 biologist (生物学家）
No.2 gravity （重力,引力）
No.3 climate （气候）
No.4 unbelievable (难以置信的,不真实的）
No.5 envelope (信封)
注：可能还有其他的单词也可以如此翻译