英语改错题

Question

It's good manner for an Arab standing close to his friend when they are talking.
这是个改错题，到底有几处错误，求详细解释 谢谢

Answer 1

1.good manners有礼貌，必须用复数
2.to stand
for sb to do sth是词组
这个句型是it做形式主语，for sb to do sth作真正的主语。
对阿拉伯人来说交谈时和朋友离得近是礼貌的。

Answer 2

It's a good manner for an Arab to stand close to his friend when they are talking

Answer 3

It was a good manner for an Arab stand close to his friend when they are talking

Answer 4

It's good manners for an Arab to stand close to his friend when they are talking.

Answer 5

It 's a good manner for an ........只要加一个a ，因为manner 是名词，又是可数。其它都对的。