几小时或几天以后，会出现咳嗽，开始是干咳，其后则咳粘液性脓痰。

[说明]根据逻辑意思判断，定语从句不是代表整个主句，而是修饰主句的主语cough。

5. In this way a vicious circle is set up which is difficult to break.

这样就树立了一种难以打破的恶性循环。

[说明]根据逻辑意思判断，定语从句修饰主句的主语circle，关系代词不是代表整个主句。

6. The time is not far when we can conquer cancer.

我们能够征服癌症的时间已经不远了。

[说明] 关系副词 when连接的定语从句修饰主句主语time.

7. Diagnosis can be confirmed on condition that bacteremia is demonstrated, which is said to be possible in about 70—90 percent of cases.

如有菌血症，就可确诊，据说在大约70%〜90%的病例中有出现此症的可能。

[说明]根据逻辑意思判断，定语从句修饰前句的主语bacteremia。

8. Families are not infrequently encountered in which the incidence of carcinoma in the stomach or other organs is extremely high.

经常见到一些家庭，其胃癌或其他器官癌症的发病率极高。

[说明]定语从句修饰主句的主语families.

9. All necessary measures have been taken which we think might arrest the process of the disease.

已采取了我们认为能制此病的一切必要的措施。

[说明]定语从句修语measures， we think为从句中的插入句。

10. No consistent factor in hypertension of unknown origin has yet emerged that tells us anything about mechanism apart from these few clues.

除了这些极少的线索外，对于原因不明的高血压尚没有任何可以说明其机理的肯定因素。

[说明]根据逻辑意思判断，定语从句修饰主句的主语factor，而不是主句中的名词hypertension或origin，也不代表整个主句。