___sign the contract unless you are sure you understand it.
| A．In no case should |
| B．In any case you should |
| C．In no case should you |
| D．In any case should you |
—Why was Professor Johnson unhappy those days?
—Can't you see it clearly? The only reason was that the theory he stuck to_____ wrong．
| A．proving | B．being proved | C．proved | D．was proved |
______ as the main reason for the recent world-wide economic problems is the fact that the US government would hardly accept.
| A．Regarding | B．To regard | C．Regarded | D．Being regarded |
The Apple Company had scarcely released i-Phone ______ it became one of the best-selling electronic products.
| A．than | B．before | C．while | D．when |
Electrolysis(电解)is the process ______ electric current is passed through a substance to cause a chemical charge.
| A．which | B．whose | C．to which | D．by which |
So much ______ by the poem for the Wenchuan earthquake that he decided to participate in the re-construction of the damaged region.
| A．did he move | B．he moved | C．was he moved | D．he was moved |