—If people make small changes, like taking buses instead of driving cars, it will make a big difference.

—_____. Then the traffic will be much better.

A．That’s all right

B．You are dead right

C．I don’t quite agree

D．Oh, come off it

夏天，从冰箱中拿出的瓶装矿泉水，过一会儿瓶的外壁会附着一层小水珠．这些小水珠是怎样形成的？