Some economists predict that the dollar will remain weak _______ economies abroad are expected to grow faster than that of the United States．
| A．while | B．as | C．before | D．until |
He said he would work it out himself, ________ ask nobody for help.
| A．and not to | B．but not | C．and prefer not | D．rather than |
They were swimming in the river ______ suddenly the storm started.
| A．when | B．while | C．until | D．before |
________ a difficult situation, so you should send a message to him and give some advice to him .
| A．As he is in | B．He is in | C．Being in | D．He being in |
It was dark______ we arrived at the little town .
| A．that | B．until | C．since | D．before |
—Oh, I failed again
—Don’t lose heart. One more time, ________ you will succeed.
| A．so that | B．therefore | C．however | D．and |