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 coutries 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.