Obama had responded to Zhou's suggestion ____ the US dollar was extraordinarily strong and that

there was no need to create a new global reserve currency.[ ]

A. to say            

B. said              

C. having said          

D. saying

你学习了化学知识，应该从科学的角度来明辨真伪，下列说法不正确的是（　　）

A．醋酸不是酸

B．铅笔不含铅

C．水银不是银

D．干冰不是冰