______ is where to go for a picnic.
问题描述:
______ is where to go for a picnic.
A.What they worry
B.What worries them
C.What is worried
D.What they are worried
帮忙解释一下
答
B.困扰他们的是去哪儿野餐.What worries them作主语;where to go for a picnic作表语;