It was my sister __________ first had the idea to cycle along the Mekong River from where it begins ___________ where it ends.

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A．who,to

B．which,till

C．that,till

D．whom,to

It was my sister __________ first had the idea to cycle along the Mekong River from where it begins ___________ where it ends.

［　　］

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 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．