Now that energy prices are rising so rapidly, further prices are very uncertain, and the risk _____ a new investment depending on them may fail is greater.

              A．that              B．by which             C．at which              D．in that

 I talked to the girl ______car had broken down in front of the shop.

   A. who              B. her              C. whose          D. which

The couple _____ photo I took at the party were very pleased with it.

A. whose                      B. who                  C. which                      D. what

Thousands of African-Americans cheered Obama’s being elected American President in the streets on November 4th 2008, many of ________ even cried with joy.

A. those                       B. them                        C. whom                    D. which

Venus has a dense atmosphere, _____ we know very little.                  

A. its composition                              B. whose composition

C. about which composition                D. about whose composition