太平天国军事上达到全盛时期，却又包含着隐患，主要是指

A．面临封建势力的疯狂反扑

B．缺乏政治、经济、思想上的牢固基础

C．外国侵略势力要渔翁得利

D．一系列军事行动中太平军人员的伤亡

We are at your service. Don't hesitate to _____ us if you have any further problems. [ ]

A. turn to

B. appeal to  

C. come to

D. apply to