They are Americans ．他们是美国人． 这样写对吗?

They are Americans ．他们是美国人． 这样写对吗? 问某国人时如：they are Americans他们是美国人.为什么要加s 美国人以他们的幽默感而自豪能翻译成这样吗：Americans are proud of their sense of h 英语翻译他们正在骑自行车（They are riding a bike.这样翻译对吗 还是They are riding They are Americans这个句子正确吗? they are Americans的问句是什么 Are they any chinese americans in england? They are Americans.改写句子,意思不变 they are americans有没有错 who are these?这样写对吗? they are in that box.这句话这样说对吗. 他们都是,是both are they 还是 they both are?