—You see，I’m poor in maths，you are not good at English，and...
—That’s________we should help each other.
A．when B．where C．how D．what
______I am concerned，the price of the computer is much too high，so I can’t afford it.
A．As long as B．As far as C．As well as D．As often as
Teachers recommend parents_____their children under 12 to ride bicycles to school for safety.
A．not allow B．do not allow
C．mustn’t allow D．couldn’t allow
The following are some popular websites________people can sell goods to each other.
A．where B．which C．when D．whose
______ by a snake, she was frightened of it.
A．Being bitten B．To bite C．Having been bitten D．Biting
My sister was very unhappy for _______ to the party.
A．having not been invited B．not having invited
C．having not invited D．not having been invited
