As a popular saying goes, “Everything has two sides.” Now people (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.
6. For example, … (举例阐述)For instance, …Let’s take …for example.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。
Let’s take cars for example. They not only pollute the air in cities, but make them crowed. Furthermore, they cause a lot of traffic accidents. (…, 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.
7. It is generally believed that …accepted (引证观点)thoughtheld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的使死亡率下降了。
It is generally believed (=thought) 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.8. …causes (produces, brings about, leads to, results in …)(因果关系)毫无疑问，需求的增长导致了价格的上涨。
There is no doubt that the increase in demand causes (results in/leads to) the rise in prices.