成本的反馈性控制按（）不同，可以分为材料成本控制、工资控制和管理费用控制等。 A.控

抗体与抗原结合的部位是（）

A.重链的C区

B.Fc片段

C.轻链的Ⅴ区

D.重链的Ⅴ区

E.重链和轻链的Ⅴ区

将18g水通电使其分解，可生成多少克氧气？

设：生成氧气的质量为x．

2H₂O

（按格式写出计算过程）

影响生殖器疱疹病情轻重及复发频率的因素有（）

A.性别

B.病毒型别

C.宿主免疫状态

D.年龄

数据库应用系统是指（）。

A.面向某一过程应用

B.面向某一实际应用

C.面向某一事物理

D.面向某一目标

Those of us hurrying to finish our taxes by tomorrow’s deadline will probably be subjected to thoughts of the I.R.S. (Internal Revenue Service) as an all-powerful bully. But the truth is, the government is not always a match for the tax advisors of wealthy people, so a lot of taxes will go unpaid at the top of the income scale.

Lawyers who represent high-income taxpayers earn more than 10 times what senior government lawyers do—an obvious disadvantage for the government agencies in attracting and retaining top talent. The lawyers who write our tax rules are overworked and sometimes inexperienced, so that they leave loopholes that are exploited by more experienced private lawyers. And the government always loses cases which it should win, and provides private lawyers with precedents.

As this vicious cycle shows, skimping (节约) on tax administration is a false economy. Instead, if we substantially increase government salaries and staffing levels, we can raise more revenue, with lower tax rates and less waste. Four reforms should be adopted immediately.

First, the government should focus on hiring talented young lawyers, since the pay disparity with the private sector is narrower for them. These efforts will be more effective if Congress helps new graduates repay student loans, which often are more than $100,000. A loan repayment program would be a powerful recruiting device.

Second, the government should tap another promising talent pool—recent retirees from private practice—to mentor young lawyers. The salary gap is less of an issue for retirees, and the opportunity to give back to the tax system can be quite appealing.

Third, the government should retain a small team of a dozen top tax lawyers at salaries closer to the market rate. They can serve as a rapid reaction force, deciding whether to shut down a new aggressive strategy immediately or to let it be evaluated through usual government channels.

Fourth, the government should retain private lawyers to help with high-priority projects. An important constraint is that lawyers who represent private clients may view it as a conflict to help the government. But this is not always true.

Through bar associations, private lawyers already volunteer to review proposed changes in the tax law and offer ways to improve them. Tax academics can also be a valuable and conflict-free source of expertise, since they ordinarily do not represent clients. And some tax litigators (诉讼律师) may view it as a prestigious opportunity and a patriotic service to represent the government in a tax case that could set an important precedent.

The tax system can be only as p as the people who run it, so the government has to recruit and retain the most promising talent. A tax system can be fair and efficient only when it is administered soundly.

According to the text, the most important factor to perfect tax system is to （）

A. improve tax administration

B. lower the income of private lawyers

C. ask people to pay tax through moral methods

D. change the current tax rate