按照句子顺序给图片写序号。
①They'll visit our classroom.
②They'll visit the art room.
③They'll go to the hall.
④They'll go to the library.
⑤They'll meet the teachers in the meeting room.
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25 + 25 可以直接相加,是因为两个加数( )。
沙漠中植物稀少,起决定作用的主要非生物因素是( )
对下面漫画《作秀》理解正确的是( )