Failure hurts grownups and children, but it can make a ________ contribution to your life once you learn to use it.
| A．positive | B．thorough |
| C．enjoyable | D．chief |
As is known to all, oranges are _______ Vitamin C.
A. rich in B. poor withC. short of D. good for
----- Where did you ______ our chemistry teacher?
----- It was in the supermarket ______ I saw him.
| A．come to, where | B．come across, that | C．come across, where | D．come to, that |
Yuan Longping makes ____ possible to produce more crops in the same fields with this special strain of rice
| A．that | B．it | C．this | D．it that |
Please ______ the traffic regulations.
| A．observe | B．take | C．see | D．look |
Only then ______ how much damage had been caused.
| A．had she realized | B．she realized | C．did she realize | D．she had realized |