I only called the police when I ______ everything else.
A: tried
B: was trying
C: had tried
D: had been trying
A: tried
B: was trying
C: had tried
D: had been trying
举一反三
- I stayed up all night（）to find a new solution to the problem. A: had tried B: try C: trying D: tried
- In vain ______ to convince him. A: I tried B: tried I C: did I try D: was I trying
- I think his method is worth ________. A: to try B: to be tried C: being tried D: trying
- I tried again. I had ____________ try.
- I tried to reserve a seat on the train, _____ all the seats had been booked already.