Various optional courses being available, we can choose ________ based on our own interest.
| A．either | B．each | C．one | D．it |
Why did you keep it a secret from me ? I ____ about it .
| A．should be told | B．ought to have been told |
| C．should have told | D．ought to be told |
— You ought to have called her yesterday . — Yes , I know I ____ .
| A．ought to | B．ought to have | C．ought have done | D．ought to have called |
________, the gathering crowd burst into applause.
| A．On entering the hall | B．When he took the floor |
| C．The speaker took his place | D．No sooner had the speaker entered |
AIDS is spreading all over the world at shocking speed. Where its dark _______ appears, we see pain, tears and death.
| A．shape | B．shadow | C．ambition | D．feeling |
--Listen! Someone is knocking at the door.
-- ______ be Mary. She has just been to Beijing
| A．She mustn’t | B．It can’t | C．It must | D．She may |