6. Influenza may, with almost typical chills, act like malaris, or it may, when the fever is continuous, act like typhoid fever.

[译文]流感的表现可能像疟疾，带有几乎是典型的寒战,也可能像伤寒,发热持久不退。

[说明]上句为一个并列句，前句的谓语may act被with引起的介词短语所分隔；后句的谓语may act被when引导的时间状语从句所分隔。

7. One thing still remains to be done here; to explain the origin of life from inorganic nature.

[译文]仍有一件事情要做，即从无机自然界去说明生命的起源。

[说明]one thing的同位语to explain被句子谓语所分隔。

8. The possiblity exists that serious complications will develop.

[译文]有发生严重并发症的可能性。

[说明]主句主语possiblity的同位语从句被主句谓语exists所分隔。

9. Evidence is increasing that viruses are involved in a variety of cancers.

[译文]有越来越多的证据表明：病毒与多种癌肿有关。

[说明]that引导的同位语从句说明主句主语evidence,被主句谓语所分隔。

10. If conservative measures fail to effectively control the infection, an operation is indicated.

[译文]如保守措施未能控制感染，就需进行手术。

[说明]动词不定式to control被副词effectively所分隔。

11. There seems little doubt, therefore, that when a peptic ulcer is in a stage of causing symptoms, direct exposure of it to hydrochloric acid will usually induce typical ulcer pain.

[译文]因此，当消化性溃疡处于出现症状的阶段时，溃疡直接接触盐酸通常会引起典型的溃疡疼痛，这一点似乎是没有疑问的. 

[说明]上句有多处分隔现象，that引导的同位浯从句与其所说明的名词doubt被插入语therefore所分隔；同位语从句内部被when引导的时 间状语从句所分隔；名词exposure要求支配介词to,被后置定语of it所分隔。

12. Chemotherapy should not, save in exceptional instances, be employed in the absence of a diagnosis.

[译文]除非在特殊情况下，没有确诊时不应采用化疗。

[说明]句子的谓语被介词save引起的短语所分隔。