— I tried       it out in this way, but I failed.

— Why not       it in some other ways?

A．to work; try doing

B．to work; try to do

C．working; try to do

D．to work; to try doing

中小板块的上市主要设立在（）。

A.香港证券交易所

B.上海证券交易所

C.东京证券交易所

D.深圳证券交易所