如图是关节结构模式图，请据图回答

（l）关节能灵活运动是因为[______]______内有少量滑液和[______]______表面光滑，

从而减少骨与骨间的摩擦．

（2）关节能牢固是因为[______]______把相邻两骨联系起来，其里面和外面还有很多______起加固作用．

10.  My grandfather is such a forgetful person that he has to __ many things, even his daily meals.

A．be remembered by

B．be reminded of

C．be memorized

D．be reminded