1 . 选词填空

break down, in addition to, contribute to, take up, all in all

1. At first he refused to admit his guilt, but when he was shown the evidence he_________and admitted.
2. ________, my sense of responsibility will make me a qualified volunteer.
3. His research has greatly_________our understanding of this disease.
4. English, history and geography are subjects which________ much time in school.
5. ________ giving a general introduction to computers, the course also provides practical operation.