题目

如右图所示，两端分别站着一个大人和一个小孩，杠杆平衡。如果他们同时都以相同的速度向支点缓慢走去，杠杆将(   )A.小孩那端下沉B.大人那端下沉C.仍保持平衡D.无法确定 答案：AAt the age of 29，Dave was a worker，________ in a small apartment near Boston and ________ what to do about his future.A．living；wondering B．lived；wondering C．lived；wondered D．living；wondered