Adder-subtractor

adder ['ædə]

n. 加法器，（欧洲产）蝰蛇（小毒蛇），（北美产无毒的）猪鼻蛇;

subtractor

[计] 减法单元, 减法器, 减数

Ask me another question.

别问我这个。

Besides the required courses, I'm taking an elective in the Lab Science.

除必修科目外，选修科目我选了实验科学。

Here are some more tips on becoming a good listener. First, take turns to listen. Don't all try to speak at the same time when you are in a group. Listen without interrupting, and stop others from interrupting. Then it will be someone else's turn. That wa

我们还可以对怎样作个好的倾听者提出几点意见。第一，轮流地听。当你们在一起时，不要同时争着说话。听的时候不要打断人家的讲话，还要阻止别人插话。然后再轮到另外的人讲话。这样，每个人都有说话的机会，也有人家恭听你说话的机会。