It took us ________ to finish the experiment on the monkey

A．an hour or two

B．one or two hour

C．one and a half hour’s time

D．one hour and a half time

关节的组成是

A．关节头、关节囊、关节窝

B．关节面、关节腔、关节囊

C．关节囊、关节软骨、关节面

D．关节面、关节韧带、关节腔