roll-on

I don't know the professor call the roll or not.

我不知道教授是不是已经点了名？

I don't know if the professor had the roll call or not.

我不知道教授是不是已经点了名？

I don't know whether the professor call the roll or not.

我不知道教授是不是已经点了名？

I do not know whether the professor call the roll

我不知道教授是不是已经点了名？

I do not know if the professor had the roll call or not.

我不知道教授是不是已经点了名？

Now, I'm going to call the roll.

现在我要开始点名。

At first, I'll call the roll before class.

首先，我要点点名。

Now I'm going to call the roll.

我现在开始点名。

I don't know whether the Pro. call the roll.

我不知道教授是不是已经点了名？

Let me call the roll once more.

让我再点一次名

However, as the name（read－only memory）implies, CD disks cannot be written onorchanged in any way.

然而，正如其名字所指出的那样，CD盘不能写，也不能用任何方式改变其内容。

Galvanizes steel pallet is mainly export which suits standard packing of European Union, the North America. galvanizes steel pallet is suitable to heavy rack. Pallet surface can design plate type, corrugated and the gap form, satisfies the different requirements.

镀锌钢托盘多用于出口，替代木托盘，免薰蒸，符合欧盟、北美各国对出口货物包装材料的法令要求；喷涂钢托盘适用于重载上货架之用，托盘表面根据需要制作成平板状、波纹状及间隔形式，满足不同的使用要求。