属于必需脂肪酸是（） A.亚油酸、亚麻酸、花生四烯酸 B.油酸、亚麻酸、花生四烯酸

（2011年湖北襄阳，15题）金刚石、石墨和C₆₀都是由碳元素组成的单质，下列说法正确的是（ ）

A．它们是同一种物质

B．它们碳原子的排列方式不同

C．它们的化学性质不同

D．它们的物理性质相同

患者女，59岁，因“左侧锁骨上淋巴结无痛性进行性肿大，伴乏力”来诊。发病过程中伴皮肤瘙痒及皮疹，发热2天，体温37.8℃，6个月内体重下降5kg，无盗汗。患者无乙型病毒性肝炎、结核、糖尿病、胃溃疡及高血压史，感染筛查阴性。淋巴结活检病理：弥漫大B细胞淋巴瘤。免疫组织化学：CD20（+），CD10（-），Bcl-6（+），MUM-1（-）。分期检查：双颈部、锁骨上、纵隔、腹腔、腹膜后及盆腔淋巴结肿大，直径均大于2cm，脾内有多发占位，最大直径约3cm。

一线治疗方案以及使用周期是（）

A.利妥昔单抗+环磷酰胺+多柔比星+长春新碱+泼尼松（R-CHOP方案），4～6周期

B.环磷酰胺+多柔比星+长春新碱+泼尼松+依托泊苷（CHOP-E方案），4～6周期

C.环磷酰胺+多柔比星+长春新碱+泼尼松（CHOP方案），6～8周期

D.R-CHOP方案，6～8周期

E.多柔比星+博来霉素+长春新碱+氮烯咪胺（ABVD方案），6～8周期

F.放射治疗

男性，32岁，胃溃疡史3年，今突上腹剧痛，面色苍白，大汗。查体：全腹压痛，腹肌紧张，似穿孔。

胃溃疡穿孔在哪一部位多见（）

A.胃体

B.胃小弯

C.胃大弯

D.胃窦

E.胃底部

使用721型分光光度计时，仪器在100%处经常漂移的原因是（）。

A.保险丝断了

B.电流表动线圈不通电

C.稳压电源输出导线断了

D.电源不稳定

E.潮湿

More than 40 million Americans between the ages of 5 and 18 attend schools throughout the United States. About 2 million school-age children are taught at home. While home schooling offers an alternative to the school environment, it has become a controversial issue.

Many public school advocates take a harsh attitude toward home schoolers, perceiving their actions as the ultimate slap in the face of public education and a damaging move for the children. Yet, as public school officials realize they stand little to gain by remaining hostile to the home-school population, the hard lines seem to be softening a bit. Some public schools have moved closer to tolerance, and，even in some cases, are seeking cooperation with home schoolers. " We are becoming relatively tolerant of home schoolers. Let’s give the kids access to public school so they’ll see it’s not as terrible as they’ve been told, and they’ll want to come back, " says John Marshall, an education official.

Perhaps, but don’t count on it, say home-school advocates. Some home schoolers oppose that public school system because they have p convictions that their approach to education—whether fueled by religious belief or the individual child’s interests and natural pace—is best. Other home schoolers contend " not so much that the schools teach heresy, but that schools teach whatever they teach inappropriately." "These parents are highly independent and strive to ’take responsibility’ for their own lives within a society that they define as bureaucratic and inefficient. " says Van Gallon.

But Howard Carol, spokesman for America’s largest teachers union, argues that home schooling parents are trying to hide their children from the real world, says Van Gallon. " Maybe we are going to run into people with problems, people that have a drug problem, people that have an alcohol problem, and teenage pregnancy. We have many problems that happen in our society and many of the children are victims. But shielding the children from the real mix of what happens every day is denying them something that they are going to need later in life. " Mr. Carol also questioned the competence of parents as teachers though he admitted that some home schoolers do better academically. " We want to make sure that a student is not denied the full range of curriculum experiences and appropriate materials, especially now with the new technology that is being introduced and the costs involved there. "

" The success of home schooling has been documented in standardized test scores administered by public school officials, " says Frank Bernet, the executive director of the National Association of College Admission Councilors. " I know why they are doing it, but I wonder why they can’t work with school officials and teachers to make the school what they want it to be. " The response from home schoolers: " We have tried that. NOW it’s time to strike out on our own. \

The author writes this passage to show that（）

A. public school is becoming more and more inefficient

B. public school is still preferred by the majority

C. home schooling becomes an alternative to public schools

D. opinions differ over home schooling