生物学
真题回顾：
【讲课要点】：生物学理论: plant invasion. 一种新树到新的ecosystem中会destroy the ecosystem
【举例说明】：
1. 一种树，本来是来解决问题的，问题是解决了，但是造成了新问题：来了后，长得太高了，导致其他树晒不到阳光了
2. 一种树，非常attractive，但是use lots of water, other trees can not survive。.
参考范例：
The lecture tells us that plants can be totally harmless most of the time. But when inappropriately brought into an environment, plants can also cause disasters by breaking ecological balance in local areas, which is biologically identified as plant invasion. Then the professor goes on to explain that by giving two examples. One is that a tree was introduced into South Africa for the purpose of stabilizing the local sand dunes. The tree fulfilled its task very successfully, but the bad news is that the tree grew so tall that they left very little sunlight for their neighboring plants. Threatened by this intruder, many plants started to lose their former territory. Another example is about a tree which was brought into Western United States for its good appearance. It seems not so large, but it has very developed root system, so it absorbed twice the water as other plants of similar size. Also, it reproduced very fast. With its rapid growing, many other local plants gradually died out because of lack of essential water resource.
在这场关于生物学的讲座中，professor通过以两种不同特点的树为例，解释了生物学理论: plant invasion。
科技类
真题回顾：
【讲课要点】：科技课。讲了发明创造的两种出现方式：
【举例说明】：
1. 有意出现：双焦眼镜(bifocal glasses)
2. 无意出现：X-rays
参考范例：
In the lecture, the professor tells about the new technology’s coming up and changing in our daily life. He explains that there are two ways in which those inventions and innovations happen: intentionally and accidentally. Then he takes bifocal glasses for example to illustrate intentional discoveries. Before the bifocal glasses were invented, people had to carry two pairs of glasses wherever they went. One was for seeing things far away, and the other for closer views. Therefore when bifocal glasses were invented, they immediately became popular among many people because of the great convenience provided. He goes on to give another example of accidental innovation. When people first encountered X-ray in the lab, the scientists had no idea of what this finding meant, or where to put this discovery into application.
在这道科技类的题目中，professor在讲座中，列举了bifocal glasses和X-rays来诠释科技发明的两种出现形式：intentionally and accidentally。
