They boy said ________ couldn’t he work out the problem but his teacher didn’t know how to do it.

A．though

B．never

C．hardly

D．not only

Ⅰ型强心苷糖与苷元正确的连接方式是

A．苷元C₁₄-O-(α-羟基糖)_X
B．苷元C₃-O-(2，6-二去氧糖)_X-(α-羟基糖)_Y
C．苷元C₃-O-(α-羟基糖)_X
D．苷元C₁₄-O-(6-去氧糖)_X-(α-羟基糖)_Y
E．苷元C₃-O-(6-去氧糖)_X-(α-羟基糖)_Y