They must try to _________ the boundaries of knowledge. 

— I think students should have mobile phones to call their parents.

— _____They often use them to play games instead.

—                      

— It's lovely. I have never been to such beautiful place like that.

They          since last night. They are about to finish the work. 

When people are surrounded by ______ communication and encouragement, they can find the courage to try, fail, redo, and try again.

—                      

— According to law, they refer to transportation, construction, finance, insurance and the like.

They should never try to pursue profit      health and life of people.

They are trying to make a new product——the world's smallest __________ robot.

We should try our best to       the children from danger.

Children often dream of ________ they want to become when they grow up．

      your customers what they need and more than they expect will lead customers to return to you. 

—Great! Maybe from now on, I should try to buy goods online.

—                      

We try our best to      your requirement.

I have to      the profit from last month.

When people are surrounded by ______ communication and encouragement, they can find the courage to try, fail, redo, and try again.