They are over 500 people in the shopping mall at weekends.对over 500 提问They are chatting with each other on the phons.对chatting with each other 提问Some students spend much money on snacks every year.改同义句

They are over 500 people in the shopping mall at weekends.对over 500 提问 ---How many people are (there) in the shopping mall at weekends.这句你的开头应该是-thereThey are chatting with each other on the phons.对chatting with each other 提问---What are they doing on the phone ?
--
Some students spend much money on snacks every year.改同义句--- It takes som students much money to buy snacks every year.
---Some students spend much money (in)buying snacks every year.---Buying snacks costs some\many students much money every day.

第一句，应该是There are over 500....吧？不是They are.
第二句，on the phons?还是on the phone?

参考答案
1\ How many people are there in the shopping mall at weekends?
2\ What are they doing on the phone?
3\ Some students pay much money for snacks every year.或者Some students spend much money in buying snacks every year.或者It costs/takes some students much money to buy snacks every year.不知道你要用哪种短语或句型同义替换。

希望帮到你。

They are over 500 people in the shopping mall at weekends.对over 500 提问- How many people are there in the shopping mall at weekends
They are chatting with each other on the phons.对chatting with each other 提问- What are they doing on the phone
Some students spend much money on snacks every year.改同义句- Some students spend much money buying snacks every year.
或：It takes som students much money to buy snacks every year.
不明白的再问哟,请及时采纳,多谢 !

how many peple are in the ........句子剩下的
what are they doing
Some student pay/cost/take/waste much money for snacks every year