It was my sister      first had the idea to cycle along the entire Mekong River from ______ it began to where it ends.

A. who; which           B. who; where          C. that; which           D. that; what

It was my sister ________ first had the idea to cycle along the entire Mekong River.

A. who                      B. whom                          C. /                              D. which

It was my sister ________ first had the idea to cycle along the entire Mekong River from ________ it begins to ________ it ends．

1. A.
   who, where, where．
2. B.
   that, that, where．
3. C.
   whom, where, that．
4. D.
   that, where, that．

It was my sister ______ first had the idea to cycle along the entire Mekong River.

1. A.
   who
2. B.
   whom
3. C.
   /
4. D.
   which