A：x2 与 1x
B：﹣m3与n3
C：23 a2b与2ab2
D：22与32
在青春期，我们总喜欢拿自己的方方面面与他人比较：比成绩、比相貌、比谁更受老师和同学欢迎……有了比较就会产生一些困惑和烦恼。排解青春期的困惑和烦恼的有效方法有（ ）
①向老师和家长求助 ②与同学和朋友交往沟通
③学会当自己的心理医生 ④相信自己，排斥他人
- Is Jack in the next room?
- Well, it's hard to say. But I heard him ________ loudly when I passed by just now.
The new film The Left Ear by Su Youpeng a few months ago, who is also a famous singer.
