Earth is believed ______ by an object the size of Mars at some point in the distant past  

before its surface cooled．

       A．to be hit   B．to have hit       C．to have been hit       D．to hit

_______ more to be pitied than blamed．

       A．Uneducated are              B．Uneducated is  

       C．The uneducated are  D．The uneducated is

By the time you have completed the essential training, you _____ exposed to virtually every new feature of the course．

       A．are    B．will have been  C．have been        D．will be

If nature does not provide man with the necessary material, it is the laboratory ____ he will turn to for it．        

       A．where       B．that   C．which       D．what

When the man came in, gun in hand, we all stood there, ________．

       A．astonished                B．astonishing             

       C．being astonished             D．having astonished

If the dog hadn’t woken us, we wouldn’t have noticed the fire and it _______ to the house next door．

       A．could spread          B．should have spread  

       C．would spread           D．might have spread

This library has available _____ you want to borrow for your school．

       A．as children’s many books as    B．as many children’s books as

       C．children’s books as many as    D．children’s as many books as

The knee is the joint ______ the thigh bone meets the large bone of the lower leg．

       A．when B．where       C．which       D．that  

It’s really ____ fun to walk alone with _______ full moon hanging in the sky．

       A．a; the       B．a; 不填    C the; a   D．不填; a    

--- Beg your pardon, but I didn’t follow you．

     --- Oh, I ______ myself．

       A．would talk to   B．talked to C．had talked to    D．was talking to