176．As a popular saying goes, "everything has two sides." Now the public are benefiting more and more from scientific and technological inventions. On the other hand, the progress of science and technology is bringing us a lot of trouble. People in many countries are suffering from public hazards.

　　常言道：事情总是一分为二的。如今人们从科技发明中得到越来越多的好处。另一方面，科技进步也给我们带来了许多麻烦。现在许多国家 的人民饱受公害之苦。

　　177．Let‘s take cars for example. They not only pollute the air in cities, but make them crowded. Furthermore, they are responsible for a lot of traffic accidents. The noise made by cars disturbs the residents living on both sides of streets all day and night.

 　　就拿汽车为例。汽车不仅污染城市空气，而且使城市拥挤不堪。此外，汽车造成许多交通事故。汽车所产生的噪音使居住在街道两旁的居民日夜不得安宁。

　　178． It is generally believed that the chief reason for the increase in population in developed countries is not so much the rise in birth rates as the decline in death rates as a result of the improvement in medical care.

　　普遍认为，在发达国家人口增长的主要原因与其说是出生率的上升，还不如说是由于医疗保健的改善使死亡率下降了。

　　179．There is no doubt that the increase in demand caused the rise in prices.

　　毫无疑问，需求的增长导致了价格的上涨。

　　180．Additional social stresses may also occur because of the population explosion or problems arising from mass migration movements-themselves made relatively easy nowadays by modern means of transport.

　　由于人口的猛增或大量人口流动（现代交通工具使这种流动相对容易）引发的种种问题也会对社会造成新的压力。