—The hall      for international conferences is of great importance.

—I see, and we are sure to complete it on time.

A．built

B．to be built

C．having been built

D．building

原地稳钩跟车到（），再向回跟车。

A、最大摆幅

B、最大摆幅的一半

C、1/4最大摆幅