-If you have time tonight,I’d like to invite you to a ball.
-That’s very nice of you,but are you ____?
A. free B. careful C. serious D. true
-If you have time tonight,I’d like to invite you to a ball.
-That’s very nice of you,but are you ____?
A. free B. careful C. serious D. true
A
C。 serious:严肃的;认真的。"你是当真吗?"