问题
选择题
Climbing hills__________of great help to health.
A.is
B.are
C.were
D.be
答案
A
非谓语动词短语作主语时,谓语动词常用单数形式。
Climbing hills__________of great help to health.
A.is
B.are
C.were
D.be
A
非谓语动词短语作主语时,谓语动词常用单数形式。