—I'm not sure _____there are living things on other planets or not.—Even scientists aren't
—I'm not sure _____ there are living things on other planets or not.—Even scientists aren't sure about it.
题目简介
—I'm not sure _____there are living things on other planets or not.—Even scientists aren't
题目详情
—I'm not sure _____ there are living things on other planets or not.
—Even scientists aren't sure about it.
B. where
C. why
答案