(单选题)17: We are now certain ____________ cigarette smoking is harmful to our health.
A: that
B: what
C: if
D: for
(责任编辑:admin) |
(单选题)17: We are now certain ____________ cigarette smoking is harmful to our health.
A: that
B: what
C: if
D: for
(责任编辑:admin) |