Apple has given in to intense pressure from Chinese state media about its customer service practices, ________  to consumers in its second-largest market.

A．apologizing

B．apologize

C．having apologized

D．to apologize

AIDS的发病机制包括()

A．淋巴因子减少

B．B淋巴细胞分化障碍

C．T细胞毒反应减低

D．中性粒细胞吞噬功能增强

E．T细胞分化障碍