我们可以一起发现答案。

come up with (an answer)意思为find or produce a way to solve, or an answer “发现， 产生/解决办法或答案”。但是，不能说An idea is come up with。如：

— He came up with an idea for making kite.

— How could he come up with this idea?

— 他想出了做风筝的办法。

— 他怎么想出这个主意的?

3. We just need to keep working on it and not give up.

我们需要坚持做下去，不能放弃。

(1)keep dong sth.意思为“继续做某事”或“不断/反复做某事”。如：

Keep reading, and your English will be better and better.

坚持阅读，你的英语会越来越好。

Keep on doing something也是继续做某事的意思。但是，此时表示在持续的过程中时有间断。如：

He is a famous writer. He keeps on writing every day.

他是一位著名的作家。他每天都坚持写作。

work on sth意思是“从事……工作”如：

The writer is working on a new book. The scientist is working on a new plan. We must work hard on all subjects.

这位作家正在写一部新书。科学家正在研究新计划。我们应该努力学习各门功课。

(2)give up 意思为“放弃，停止”，后面可跟动名词形式作宾语。如：

Give up smoking! It’s no good to you! 戒烟!烟对你没好处!

I can do nothing more. I have to give up.

我无能为力，只好放弃。

4. Which of these do you think is the second most useful invention?

你认为哪一个是第二有用的发明?

(1) do you think 是插入语，常置于疑问词之后，不能置于疑问词之前，作“你认为……”解释。如：

— How old do you think my father is?

— I think he’s fifty.

— 你认为我父亲多大年纪了?

— 我想有五十岁吧。

— Who do you think will teach us English this term?

— Mr Li, I think.

— 你认为这个学期谁将教我们英语?

— 我想是李教师。

(2) 在最高级前加系数词second, third…，表示程度比较次要，意思为“居第二/ 第三位的……”。如：

Changjiang River is the longest one in China. And Yellow River is the second longest one.

长江是中国最长的河流，黄河是第二长河。

Bill is the second tallest in our class.

比尔在我们班上身高第二。

(3) 注意词型的转换：invent v. 发明

invention n.. 发明(物)

inventor n.. 发明家(者)

Edison was a great inventor. He invented lots of things. During his lifetime, he had 1093 inventions.

爱迪生是个伟大的发明家。他发明里许多东西，一生中有1093项发明。

5. When he was a child, he was always asking questions and trying out ideas.

当他还是个孩子的时候，他总是问一些问题，试验一些新的想法。

(1)always与进行时态连用，表示说话人厌烦、赞赏、不满、批评等情感，意为“总是……”。如：

The girl behind me is always talking in class.

坐在我后面的女生上课总是讲话。 (表示厌烦)

The PLA are always doing good deeds for the people.

人民解放军总是为人民做好事。 (表示赞赏)

(2)try out 意为“试验;试用”。如：

The inventor is excited, and he is going to try out his new machine. His idea sounds fine, but we need to try it out in practice