高一必修一课本第一单元有一句话是I wonder if it'sbecause i haven't been able
高一必修一课本第一单元有一句话是I wonder if it'sbecause i haven't been able to be outdoors for so long that i've grown so crazy about everything to do with nature.这句话中的outdoors 不是副词吗,为什么跟在be动词后面?不是说 be动词后面常跟一个形容词作表语吗? 还有一个问题 He came here 3 years ago. He has been here 3 years ago. 这两句话对吗?如果有错的话错在哪里?