I can hardly imagine ______ little children can work out the problem in _____ short a time. 

With so many debts to pay back, the company was in serious __________ difficulty.

(2013·安徽安庆三模)The two countries agreed to ________ their differences and work together for peace, which has a positive effect on the international situation.

 Some Southeast Asian countries were quick to ________ the search for a missing Malaysian airliner--Malaysia Airlines Flight 370.

(2013·江西六校二模)University is ________ most worthwhile time of discovery and learning, and it is also ________ very enjoyable and valuable experience for every one of us.