Human facial expressions differ from those of animals in the degree __________ they can be controlled on purpose.

Male nurses can see things from a different angle than women and bring a male way of thinking _____problems.

Be careful when you cross this busy street. If not, you may run over by a car.[ ]

Mum, I think I’m ________to get back to school.—Not really, my dear. You’d better stay at home for another day.

－You’ve dropped __________ “s” in the word “across”.－Oh, you are right, __________ letter “s” should be doubled like this “cross”.