On Halloween, children in American like to _____ as ghosts to frighten people.

Some of the drivers were ______ by the police because of their good behavior in the traffic accident.

---Which color do you prefer, red or black? ---Red. For red_____a sense of energy and strength.

As nobody here knows what is wrong with the machine, we must send for an engineer to ____ the problem.

 Yahoo recently announced to ________ 2,000 employees, about 14% of the company’s workforce, aiming to save $375 million annually.