They are only study(还是studying) for long time.
问题描述:
They are only study(还是studying) for long time.
答
studying
答
be only doing
固定搭配
答
studying
虽然study可以用作名词 表示学习 不过用在这里不通啊 你不能说他们是学习
答
当然是studying
be doing 固定句式
答
studying
有are了,当然是studying
答
studying
这是现在进行时态,由主语+be+动词-ing(现在分词)构成