They have a class meeting every morning.(对划线部分提问)（划线的是every morning）有两句第二句是：They come from America.(改为同义句)

1 How often do they have a class meeting？
2They are from America 或者 They are American

1. How often do they have a class meeting? 第一句问频率，多久一次how often
2. They are from America.第二句中come from=be from. 主语是they，be动词用are

How often do they have a class meeting?
They are from America 或 They are American.

When do they have a class meeting?
They are from America.

1. When do they have a class meeting?
2. They are from America.
be from = come from 来自
有不明白的地方再问哟,祝你学习进步,更上一层楼! (*^__^*)