Only when I made it to the train station _______ that I had left my ticket at home.

I never go to school late, _________.

To fight SARS, we should ______ animals.

Interviews were carried out ________ over the telephone，via e－mail or fax or face to face in four cities including Beijing，Shanghai，Guangzhou and Wuhan

What did your parents think about your decision?—They always let me do _____ I think I should.