James has just arrived,but I didn't know he came until yesterday 正确答案是James has just arrived,b
回答：he came是他来了,昨天他还没来呢,他要来而已
疑问：上面回答的意思是他昨天没来,这个信息是从james has just arrived得来的吗,
现在完成时不是表示过去发生并且已经完成的动作对现在造成影响或后果,所以我觉得也可说明JAMES昨天就来了,我这么想对吗,还是不明白为什么不能用came