Swimmers must be very strong in order to build up speed because of the high resistance of the water. Runners, ____, must struggle against the heavy resistance of the air and ground.

A．generally

B．similarly

C．naturally

D．probably

关于错畸形矫治后需要保持，其说法不正确的是（）

A.肌动力平衡的最终改建尚未完成

B.牙周膜纤维张力未恢复平衡

C.的平衡尚未建立

D.第三恒磨牙的萌出

E.生长型不会影响矫治效果，保持时不用考虑这一因素