1.The man has ___ lonely since his wife left .A been B got C

1.The man has ___ lonely since his wife left .A been B got C become D turned
2.Thr light is off.Mr wang _____be in the office,
A must B mustn't C can D can't
3.____ a pleasant life we are having in the century .
A what B what a C how D how a
请帮我讲解一下.

1.选A,has been + 形容词,表示某一种状态已经持续一段时间
2.选D,can't be表示不可能,这句话意思是：灯已经关了,王先生不可能在办公室里.
3.选A,这是一个感叹句.what a / an .多么...的.啊