As the price of oil keeps__________,people have to pay more for driving a car.

单项选择题Only when we hurried to the airport__________the flight was canceled.

单项选择题John had never been abroad before, __________he found the business trip very exciting.

单项选择题How much does it __________to take the online training course

单项选择题In the long run it is far cheaper to__________the needs of poor people than to ignore them.

单项选择题Can you__________your can up so that I can get through !