英译汉：It is my Science homework today.____________________________

英译汉：Don’t walk on the grass!_________________

英译汉：Helen travelled round the world. 
___________________________________

翻译下列句子。
1. I can’t go to school because I have a bad cold.
________________________
2. Don’t worry about your lessons.
________________________
3. My mother will take me to the doctor.
________________________
4. Take good care of yourself.
________________________
5. Sorry, I have a cough.
________________________

It's a chair. （   ）

A．它是一张桌子。

B．它是一把椅子。