It is difficult for us to ______  our conversation with all this noise around us.

It would be _____ a risk to let the child go to school by himself.

To our anger, many poverty-stricken counties build luxurious office buildings instead of _______ money to improve the miserable conditions of local schools.

Leaders of many countries have been trying to ______ what it is that makes China develop so fast. 

If your mother doesn’t agree, there is nothing you can do____than stay at home.