使生物碱碱性减小的吸电子基团是 A．烷基 B．羰基 C．醚基 D．苯基 E．酯基

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Scientists have not come close to understanding all the different kinds of life on the planet, but US researcher Craig Venter is already working on creating the first artificial（人造的）life.

Venter and his researchers made a breakthrough late last month, They successfully moved the DNA of one type of bacteria(细菌) to a yeast cell（酵母）, changed it, then put it into another bacterial cell.

“Bacteria have systems that protect them from foreign DNA” Venter explained to the BBC, In the experiment, the team managed to block this system.

The experiment was performed on a simple type of bacteria celled mycoplasma mycoides. The team took the bacteria’s genes and put them into a yeast cell.

Putting a DNA in a yeast cell allowed the team to change the genes in this case, taking out a gene that was not necessary for the bacteria to live.   

They then put the gene into a host bacteria cell. The cell went on to divide normally, producing new healthy bacteria.

In January, the team created artificial genes of a new type of bacteria. Their next goal is to put the artificial DNA into a host cell to create a new species, according to a report in Science magazine.

“lf we don’t make any errors, I think it should work and we should have the first artificial species by the end of the year.” Venter said in the report.

The first artificial life form is likely to be a simple man-made bacteria, to prove that the technology can work.. But that form will be followed by more complex bacteria that turn coal into cleaner natural gas, or algae  that can take in carbon dioxide and change it into fuel.

Many scientists think it’s good news to have this artificial life, but others are worried that the technology to create new organisms might end up in the wrong hands, with dangerous result.

57．Which of the following is true according to the text ?

A  Bacteria have systems that protect them from yeast cell.

B  If we put a gene into a host bacteria cell,the cell will not go on to divide as usual.

C  Venter and his researchers completely achieved all their goals.

D  All the scientists didn’t agree to this artificial life.

58. What can we learn from the underlined sentences?

A. Venter and his researchers had succeeded in this project.

B. Venter predicted that they would make errors in the future,so he decided to give it up.

C. Venter would go on the study and he was full of confidence.

D. Venter was a clearer man but a little shy.

59. Which of the following shows the order of the passage ?

1.change the genes

2. put the gene into a host bacteria cell

3. moved the DNA of one type of bacteria to a yeast cell

4. The cell went on to divide normally

5. put it into another bacteria cell

A. 3-5-1-4-2     .               B. 3-5-1-2-4   C. 4-2-5-1-3                      D. 2-3-5-1-4

60.What will be mentioned in the next paragraph?

A. The wrong hands that created by the artificial life.

B. The advantages and disadvantages about the artificial life.

C. The future about this project.

D. The author’s attitude.

甲公司20×6年12月31日，X在产品的成本为500万元，该在产品中50%已订有不可撤销的销售合同，销售合同约定的售价总额为700万元，其余加工中的X产品无销售合同且其预计售价总额为650万元。预计为销售该产品所需发生的费用和相关税金合计为 80万元，进一步加工所需费用为360万元。甲公司20×6年12月31日，X在产品的可变现净值为( )万元。

A．410
B．490
C．770
D．910

水力稳定性

除经批准允许单独巡视设备的人员以及检修工作的工作负责人外，其他人员都不许单独进入或滞留在高压室内和室外高压设备区内，对不对？

简述烘干漆比气干漆具有较好的防腐能力原因？