38. ---I can’t find Mr. Zhang. Where did you meet him this afternoon? ---It was in the classroom _______ he taught.
______ about wild plants that they decided to make a trip to Madagascar for further research
Unlike watching TV, reading is a highly active process _______ it requires attention as well as memory and imagination.
---- Don't you think it necessary that he _______ to Miami but to New York?---- I agree, but the problem is ________ he has refused to.
The place _______ the bridge is supposed to be built should be ________ the cross-river traffic is the heaviest.
---- The woman biologist stayed in Africa studying wild animals for 13 years before she returned.---- Oh, dear! She _______ a lot of difficulties!