In English class, our teacher often creates an environment _____________ we are given the opportunity to solve problems ourselves.
I recognized him_________ I saw him in thecrowd.
We don’t have enough meat in the fridge.— I _______ some more in the supermarket soon.
下列各句中加点的成语,使用恰当的一项是( )
Why didn’t you answer the phone last night?—I ___ when you called. [ ]