This problem may lead to more serious ones if ______ unsolved.
| A．making | B．remained | C．keeping | D．left |
“The impact will only growIran’s leaders decide to change course and meet their international obligations,” US Secretary of State Clinton warned．
| A．in case that | B．provided that | C．unless | D．until |
I was standing atop a North Carolina mountain, the afternoon sun______like golden lace through the trees．
| A．threaded | B．threading | C．being threaded | D．was threaded |
Some people claimthe rumor that some Egyptians are planning a 100,000 people anti-government protest．
| A．to overhear | B．to have overheard |
| C．having overheard | D．to be overheard |
In his lecture, the professor referred to the belief, in contrast to all other countries, ______the elderly are wise, ______is particularly dominant in the Chinese culture．
| A．that; one that | B．that; that | C．which, which | D．that; one |
—Please go on with your demonstration．
—But where was I?
—Well, you_____the two chemicals together．
| A．tried to mix | B．were trying to mix |
| C．were trying mixed | D．had tried to mix |