I was ①reading a book ②in my room ③when my friend

问题补充：

I was ①reading a book ②in my room ③when my friend ④called me 去掉哪一个?

答案：

2======以下答案可供参考======

供参考答案1:

4绝对错 WAS都有了 后面用原型或doing 其他的 我不太清楚 我也是名学生额...

供参考答案2:

可以不去。句子I was reading a book in my room when my friend called me .翻译：朋友打电话来时我在房间看书。如果一定要去，去②in my room 或①reading a book