1.rather than后的动词形式怎么判断?

1.rather than后的动词形式怎么判断?
也有前后不一致的情况,那要怎么判断?
2.Why did you decide to go back to school?
I am tired__as a secretany.
Afor work Bof working
Cto work Dabout working
3.They failed to pass the exam last time.Iregretted__them.
Ato be not seen B not to see
C not be abie to help Dbeing unable to help
4.__by a greater demand for vegetables ,farmers have build more green house.
A.Driven B Being driven
C.To drive D Having driven
5.Accustvmed to__the steep mountains,he had no difficuly reading the top.
A climbing B climb
C.having climbed D.have climbed