I know it’s normal for such a thing to happen，but we________it if we’d been more careful.

(2013·新课标全国卷Ⅰ)Try not to cough more than you can ________ since it may cause problems to your lungs

. I was wondering what it is _____ has made her so popular with her workmates.

The weight of the moon is only about _____ of that ofthe earth

Most of that country’s external debt is ______ private banks.[ ]