Thank you for a great evening. I really enjoyed __________

单项选择题He was speaking so fast（）we could hardly follow him.

A．what
B．as
C．but
D．that

单项选择题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