1 If headaches only occur at night, lack of fresh air is often the cause.
    A．deliver
    B．fall
    C．happen
    D．a(chǎn)rrive
    2 The ice is not thick enough to bear the weight of a tank.
    A．suffer
    B．a(chǎn)ccept
    C．receive
    D．endure
    參考答案：1. C 2. D