为什么Mars is not an easy place to live on而不是to live?求老师们详细的语法讲

为什么Mars is not an easy place to live on而不是to live?求老师们详细的语法讲 火星不是一个容易居住的地方是Mars is not a easy place to live on 还是to live live in Mars还是live on Mars 为什么 my cousin( ) on an island.A.lives.B.live.C.is live D.to live My cousin on an island.A.live B.lives C.is live D.to live I think that world will be an easy place to live in. 完形填空 ”I think that the work will be an easy place to live in 英语翻译I think the world will be an easy place to live in.We wi i think that the world will be an easy place to live in. The room is big enough for us______.为什么是to live in而不是to live This is the place to live 有一个句子It is a nice place to live为什么Live后不加ＩＮ