Complete each of the following sentences with the proper form of the word in brackets. Write your answers on the ANSWER SHEET. （10 points, 1 point each）（difficult） Bad weather heightened the ____________for them to carry out the task.
【正确答案】：difficulty
【题目解析】：difficulty 的意思是“困难”。原句的意思是：恶劣的天气增加了他们完成任务的困难。
