Historical experience can as a most important source of information.
| A．serve | B．use | C．regard | D．prove |
It is pretty well understood __________controls the flow of carbon dioxide in and out the atmosphere today.
| A．that | B．when | C．what | D．how |
Barack Obama told millions ______ him that his grandmother's influence on ______ he is and the way he views the world was significant.
| A．watch; how | B．watching; who | C．watched; where | D．to watch; what |
There is no ________ thinking more about the matter. Take it easy.
| A．point | B．fun | C．doubt | D．need |
It's reported that by the end of this week the stock exchange________ by about 10％.
| A．will have risen | B．has risen | C．will be rising | D．has been rising |
Careful surveys have indicated that audience ________ teachers and students be more likely to take seats ________ directed.
| A．1ike; that | B．as; that | C．1ike; as | D．as; like |