A: 你们别客气。 B: 我们不客气。
客气=being very polite
A: Said from the perspective of a host to guests. Have a meaning of "welcome, and make yourselves at home." Literally means "don't be polite".
B: Said by guests. Basically saying we'll make ourselves at home (literally: we're not going to be polite). It would be better to say it like 我们就不客气了,so it will be more like "then we won't be too formal and will make ourselves at home".
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what is meaning 也 in this sentence?
我来中国的时候一句汉语也不会说。
也=not even. As in when I came to China, I couldn't even speak a single word of Chinese.
where of the sentence comes 也 ?
Not sure what you are asking above...
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what is meaning this sentence ?
他问您好。
He asks after you/ He says hello. You are basically passing on a message of greeting from a common friend.