下列每句的画线部分中有一处错误，找出并改正

1. When I got to school, I realized I left my keys at home.              

                    A                       B       C

2. She asked for my homework, and of course I didn't do it.            

                  A                               B       C

3. When I walked into class, the teacher had started teaching yet.             

                        A                                          B                      C

4. What was happened to Tina yesterday?          

            A            B       C

5. Not wonder you look very happy today.            

            A                  B         C