叶基
参考答案：
叶片和叶柄连接的一端称为叶基，形状也因植物种类不同而有差异。
按要求改写句子。
1. Please write down your name here. (改为否定句)
Please ____ write down your name here.
2. I swept the floor just now. (改为一般疑问句)
____ you ____ the floor just now?
3. She needs to wear her school uniform. (改为否定句)
She ____ ____ to wear her school uniform.
4. I often help my mum do the laundry on Sundays. (改为同义句)
I often help my mum ____ ____ on Sundays.
5. The boy is cleaning the table. (对画线部分提问)
____ ____ the boy ____ ?
低速旋转阳极X线管的阳极转速一般在
A．1800转/分B．1800转/秒C．3800转/分D．2800转/秒E．2800转/分
