15．– How cold it is! I wonder how grass survive under such heavy snow． –Don’t worry．There is a lot of air in loose snow which _______．

– Do you still remember when we wentto the Summer Palace — I can’t remember it well, but it _____sometime last July.

Does Tara work as _______ as Tina–Yes, she does.

The museum will open in the spring with an exhibition and a viewing platform ________ visitors can watch the big glasshouses being built.

Instead of praising your kids for their intelligence, you should____ your praise on the effort they put into succeeding at task, expert say