There are moments         I forget all the things       happened in the past.

Taobo is Asia's largest retail（零售的） network platform, ______ people can buy and sell many kinds of things．

He made another wonderful discovery, _________ of great importance to science.

Without facts, we can’t form a correct opinion, for we need to have actual knowledge________ our thinking.

A．which to be based on	B．which to base on
C．on which to base	D．which to base

Clearly, in a system _________ every decision is made on the basis of tradition alone, it may be difficult to achieve progress.

--- Why does she always ask you for help?   ----- There is no one else _______, is there?

She brought with her three friends, none of ___________ I had ever met before.

Whenever I met her, _________ was fairly often, she greeted me with a sweet smile. 

The best way to make a kid to be independent is to put him in a position _______ he has no one else to refer to ．  

His opinion was such a good one _________ his family all agreed to accept．