So you missed the lecture given by Professor Smith．——-____．I got there30 minutes before it finished．

They ___________to put their hearts into study..

_____ achievement, last week’s ministerial meeting ofthe environment here earned a low, though not a failing grade.

Li Yang, the founder of Crazy English, says that he copies it down _______ he comes to a sentence

Wind power is an ancient source of energy ____ we may return in the near future.[ ]