1. 美国东部有一种蜥蜴的进化历程。

2. 一个高地人民运用农产品。

3. 鸟类的羽毛形态特征。

4. 罗马帝国获得发展的优势。

5. 行星的内部结构。

Do you agree or disagree with the following statement? It is better to travel abroad to visit different countries when you are younger rather than when you are older.（重复20180204考题）

你是否同意，在年轻的时候就到不同的国家旅行，比年老的时候到不同的国家旅行更好。

Ireland is home to many stone structures called“lrish round towers” which were probably built around 1000 years ago.These buildings are round, narrow, and from eighteen to forty meters tall.While there is no clear agreement on their purpose, several theories have been suggested.

Forts

One possibility is that the towers were built as forts to protect against foreign invaders such as the Vikings of Scandinavia.Local people could hide themselves and their valuables inside the towers and wait for an attack to end. This theory is supported by the fact that the doors are located in an unusual placeInstead of being placed at ground level, the doors are located several meters above the ground.

Local people would have been able to enter a tower only by climbing a ladder that could then be pulled up into the tower.This unusual design would have allowed them to keep invaders out in the event of an attack.

Bell Towers

Another possibility is that the towers once

housed metal bells that could be rung loudly to send messages to the local population.At that time, many European towns had bell towers which were used for communication, so it is possible that the round towers served the

same purpose In fact, in the lrish language the traditonal name for the towers sounds exactly like an lrish word that literally means“bell

house”. This strongly suggests that the round towers indeed functioned as bell towers.

Watchtowers

A third possibility is that the towers functioned as watchtowers.Historians have pointed out that watchtowers were usually high structures built to allow for observations of the

surrounding areas. Since all lrish towers are tall buildings, it is possible that they were built to provide a high place from which guards or watchmen could see enemies, local

inhabitants, or visitors approaching from afar.

Q: Summarize the points made in the lecture being sure to explain how they challenge the specific theories presented in the reading passage.