问题
选择题
Such habits as smoking and cheat
ing, once________, are hard to get rid of.[ ]
A. forms
B. forming
C. having formed
D. formed
答案
答案：D
搜题请搜索小程序“爱下问搜题”
Such habits as smoking and cheating, once________, are hard to get rid of.[ ]
A. forms
B. forming
C. having formed
D. formed
答案：D