女性，30岁，因二尖瓣狭窄做了手术，术前肝功正常。HbsAg（-），术中输血800ml，40天后肝功能ALT280IU/L，AST160IU/L，Tbil18μmol/L。

最主要的预防措施是（）

A.饮食卫生

B.水源管理

C.隔离病人

D.严格血源管理

E.预防注射

The pharmaceutical industry argues that because new drugs will not be developed unless heavy development costs can be recouped in later sales, the current 20 years of protection provided by patents should be extended in the case of newly developed drugs. However, in other industries newproduct development continues despite high development costs, a fact that indicates that the extension is unnecessary. Which of the following, if true, most ply supports the pharmaceutical industry’s argument against the challenge made above

A．No industries other than the pharmaceutical industry have asked for an extension of the 20-year limit on patent protection.

B．Clinical trials of new drugs, which occur after the patent is granted and before the new drug can be marketed, often now take as long as 10 years to complete.

C．There are several industries in which the ratio of research and development costs to revenues is higher titan it is in the pharmaceutical industry.

D．An existing patent for a drug does not legally prevent pharmaceutical companies from bringing to market alternative drugs, provided they are sufficiently dissimilar to the patented drug.

E．(E) Much recent industrial innovation has occurred in products—for example, in the computer and electronics industries—for which patent protection is often very ineffective.