You’d better book the tickets in advance; _______ we may miss the concert. 

________ we looked at it, the better we liked the oil painting.

---- Do you think it's a good idea to make friends with your students? ---- _____ , I do．I think it's a great idea．

Make sure to turn off the gas after you take a bath, which would ___ cause danger.

The death toll of the quake in New Zealand is _____ 150, but officials say the figure won’t stand because they are still getting information in.