27．Don’t you think it essential that every resident of Nanjing___________spare no effort to make contributions to Nanjing 2014 Youth Olympic Games?

Most people who enjoy travelling believe that travel ______ not only our bodies but also our minds.

I wonder if you ________to the party this weekend. If you________, I will too.

What a pity! Their experiment is a failure.—They ________ better under more favorable conditions.

It is that I want to go on a trip this afternoon.—Sounds great! Let’s go!