长春市南湖公园四季风景怡人，下列景色形成过程中涉及到液化现象的是（　　）

A．春天，积雪消融

B．夏天，雾绕丛林

C．秋天，霜打枝头

D．冬天，冰封湖面

The machine has begun to ___.

A．have its work

B．take its work

C．do its work

D．show its work