【单选题】Keith doesn't seem to be his ______ self these days and we should pay more attention to him.
【单选题】Because we know more about material than ______ our ancestor, we should be able to select better ones.
【简答题】I think we should be trying to encourage more sort of(绿色交通).
【多选题】When listening to an introduction of an event, we should be more concerned with:
D.
When and where does it take place?
E.
What consequences does it bring about?