A:Ⅰ
B:Ⅱ
C:Ⅲ
D:Ⅳ
We used to see each other _____, but haven't heard from him since last year.
面对街面上层出不穷、花样繁多的“有奖销售”“买一送一”等促销行为,下面正确的做法是( )