Says who:
说谁×
谁说的?√
例句:
Says who? I doubt about it.
谁说的? 我很怀疑这事。
Puppy love:
小狗之间的爱情×
早恋√
Nowadays puppy love is not rare among middle school students.
当今中学生早恋现象不是新鲜事了。