关于"All you can do is listen to the radio and smoke too much.

1）英语语法规定：如果用不定式结构做句子表语,且其前有行为动词do或其变化形式did/does/done的时候,这时必须省略不定式符合to.
这一规定简而言之即是：前有do,后无to.
此语法现象比较常见,也是考试中经常考查内容.
2）再如：What I can do now is (to) wait here.
All you need to do is (to) fill in the form.
3）二楼也很细心：不定式并列时,一般第二个to也会省略,即and smoke too much = and (to) smoke too much.