问题
选择题
There ____________ always three lights in every country: red, yellow ____________ green.[ ]
A. is; and
B. are; and
C. are; or
答案
答案：B
搜题请搜索小程序“爱下问搜题”
There ____________ always three lights in every country: red, yellow ____________ green.[ ]
A. is; and
B. are; and
C. are; or
答案：B