Scientists think they have _____ in their attempt to find the causes of some major dieases.
| A．broken through | B．worked out |
| C．fallen out | D．got round |
Put the books back ________ they belong after you have finished them.
| A．where | B．to where |
| C．to which | D．to the place |
From their _____on the top of the TV Tower, visitors can have a better view of the city.
| A．stage | B．position | C．condition | D．situation |
—He says that my new car is a ____________ of money.
—Don’t you think those words are just sour grapes?
| A．lack | B．load | C．question | D．waste |
The World Health Organization gave a warning to the public without any______when the virus of H1N1 hit Mexico in April, 2009.
| A．delay | B．effort | C．schedule | D．consideration |
In our class, when the bell rang and the teacher closed his book, it was a ______ for everyone to stand up.
| A．signal | B．chance | C．mark | D．measure |