He trained hard in puzzle-guessing, a sort of children’s game, all year, _____ still failed to reach his best form in all the tests given to both adults and children.

A．Then 　　　　　

B．Thus 　　　　

C．Therefore

D．Yet

下列（）方法是液化石油气的装卸方法。

A、压缩机加压装卸法

B、加热装卸法

C、静压差装卸法

D、压缩气体加压装卸法

E、静压差装卸法