建安文坛的领袖，开风气之先，影响一代诗风是谁？

列综合算式计算．

（1）26与3的积比160除以5的商多多少？

（2）525除以73加上102的和再乘4，得多少？

（3）1007除以35与18的和再乘3，得多少？

北方地区的面积约占全国的______，人口约占全国的______，属于______，特点是______，年降水量一般在______，北方地区以平原为主，______是我国面积最大的平原，以肥沃的黑土地著称，华北平原主要由______、______、______河流冲积而成，和黄土高原一起被称为______．

目前女性生殖器官恶性肿瘤发生率最高的是（）

A.外阴癌

B. * * 癌

C.子宫颈癌

D.子宫内膜癌

E.原发性输卵管癌

This week marks the 10th anniversary of the Alar apple scare, in which many American consumers were driven into a panic following the release of a report by an environmental organization claiming that apples containing the chemical Alar posed a serious health threat to preschoolers. The report was disseminated through a PR (Problem Report) campaign and bypassed any legitimate form of scientific peer review. Introduced to the American public by CBS "60 Minutes", the unsubstantiated claims in the report led some school districts to remove apples from their school lunch programs and unduly frightened conscientious parents trying to develop good eating habits for their children.

Last month, Consumers Union released a report warning consumers of the perils of consuming many fruits and vegetables that frequently contained "unsafe" levels of pesticide residues. This was especially true for children, they claimed. Like its predecessor 10 years earlier, the Consumers Union report received no legitimate scientific peer review and the public’s first exposure to it was through news coverage.

Not only does such reporting potentially drive children for consuming healthful fruits and vegetables, the conclusions were based on a misleading interpretation of what constitutes a "safe" level of exposure. Briefly, the authors used values known as the "chronic reference doses", set by the U. S. environmental Protection Agency, as their barometers of safely. Used appropriately, these levels represent the maximum amount of pesticide that could be consumed daily for life without concern. For a 70-year lifetime, for example, consumers would have to ingest this average amount of pesticide every day for more than 25,000 days. It is clear, as the report points out, that there are days on which kids may be exposed to more; it is also clear that there are many more days when exposure is zero. Had the authors more appropriately calculated the cumulative exposures for which the safety standards are meant to apply, there would have been no risks and no warnings.

Parents should feel proud, rather than guilty, of providing fruits and vegetables for their children. It is well established that a diet rich in such foods decreases the risk of heart disease and cancer. Such benefits dramatically overwhelm the theoretical risks of tiny amounts of pesticides in food. So keep serving up the peaches, apples, squash, grapes and pears.

The warning message about the Alar apple was given ().

A. by Consumers Union

B. by a health center

C. through an news agency

D. through the government