All those second-hand goods are sold at ____ before．
| A．30％ as lower price as | B．30％ as low a price as |
| C．as 30％ low price as | D．30％ lower price than |
It is much easier to talk about social change than to .
| A．bring it on | B．bring it about | C．bring it up | D．bring it out |
This is a story completely by him, so don’t rust him.
| A．discovered | B．invented | C．found | D．known |
Historical experience can as a most important source of information.
| A．serve | B．use | C．regard | D．prove |
Have a good rest, you need to your energy for the tennis match this afternoon.
| A．have | B．save | C．hold | D．get |
The boy was made to the explanation(解释，说明 process of explaining) .
| A．speak | B．tell | C．repeat | D．say |