这两句话哪句对we are brother 还是 we are brothers 哪个对 为什么

英语.we are so boring.和we are so bored.哪个对?还是两个全对,为什么? We are twins We are the twins,哪个对的 We are going to Beijing tomorrow对这句话提问 I have no brother I have no brothers 两句话那句对 We are China students对呢,还是We are Chinese students对呢? brothers-in-law和brother-in-laws这两复合词的复数哪个对? we are very happy family/we are a very happy family哪个对 we all are students和we all are students 哪个对? We are a happy school life is the end of the day.这句话是对的还是错的? We are four brothers living under one roof .We are---------? 歌词because we are brothers ,because we are friends We all are 和 We are all 那个是对的?为什么?