So sudden ________that the enemy had no time to escape. 

A．did the attack

B．the attack did

C．was the attack

D．the attack was

下列颜色变化不是由化学变化引起的是（　　）

A．紫色石蕊溶液中通入二氧化碳变红

B．紫红色的铜片在空气中加热逐渐变黑

C．蓝色的硫酸铜溶液遇锌逐渐变成无色

D．滴有红墨水的水遇活性炭逐渐变成无色