It’s the sort of work that a high level of concentration.

Would you mind _____me a sweater? I feel a little cold. [ ]

GarterDruse ______ his being selected for the important task to his courage，devotion and knowledge of thearea.

Mr Cooper wanted to buy the house and he told me that ______ the house cost, it would be ______ it.

The news _____ he has passed the exam makes his parents very happy.