for it 3 many organ- isms to survive under different conditions.
父母没有预料到孩子的问题这样难回答。
________ (令学生失望的是), the books they needed were sold out at the bookstore.
______(正如我们所期待的那样), the program went smoothly.
It was after the failure of this attempt that he _________(诉诸武力).
我们无法想象在那个遥远的星球上存在什么东西。