选出句中错误并改正。( ) 1. Is careful. The bus is coming.
　　　　A 　　　　B 　　　　C
( ) 2. John, does your homework quickly!
　　　　　　　A 　B 　　　　　　C
( ) 3. Nancy, please not open the window.
　　　　　A 　　　　B 　　　C
( ) 4. Don't is late for school again.
　　　　　A B　　 C
( ) 5. Let's us play games together.
　　　　 A　B 　　　C1. A-Be 2. A-do 3. B-don't 4. B-be 5. B-去掉us / A Let