They just want us to practise getting out the school______(以免) there is a real fire one day.

And______(保证) you stay with us because the teacher will be calling roll call.

Is your seat belt______(扎) tightly?

Safety belts are the best form of protection passengers have______(万一) a crash.

She walked faster, but the footsteps behind him______(跟随) her pace.

Teresa______(感到震惊) by what she had seen.

发现做……有困难______

放手让……做______

归结为______

在……表现出色______