We considered him to be a true friend, ______did many others whom he had cheated

A．which

B．as

C．when

D．though

机械扰动和循环介质流对各种密度和粒度的颗粒都会产生不同的影响，尤其对密度接近于重介质悬浮（）影响更大。

A.细颗粒

B.中等颗粒

C.粗颗粒

D.特大颗粒