1938年H·T·dean提出“饮水氟含量与斑釉牙呈正相关,与患龋率呈负相关”。（)

A.高氟水改换为低氟水

B.用混凝沉淀法除氟

C.用活性氧化铝除氯

D.不用含氟量高的茶叶泡茶

E.不用含氟牙膏与含氟药物

A.156

B.160

C.165

D.166

A.增加钙的摄入

B.饮水除氟

C.改善土质

D.筛查重点人群

E.增加蛋白质摄入

A.批驳“速胜论”、“亡国论”

B.全面分析了中日战争的基本特点

C.科学预见了抗日战争所要经过的阶段

D.论证了抗日战争是持久的，最后胜利属于中国

A.2

B.4

C.6

D.8

E.12

A.含氮气体

B.含氟气体

C.含氧气体

A.水-氢氧化钠溶液

B.水

C.硫酸

D.硫化氢

E.氢氧化钠-硫酸肼

A.含服的时间宜短

B.含服时应把药片放于舌根部，尽量贴近咽喉

C.含片不要咀嚼，也不要吞咽

D.含完药片后在30分钟内，最好不要吃东西和饮水

E.5岁以下幼儿服用含片时，最好选用圈式中空的含片

A.1

B.2

C.3

D.4

t that's not how it (1)_____. Applicants whose parents are alums get special treatment, as (2)_____ athletes and rich kids. Underrepresented minorities are also given (3)_____. Thirty years of affirmative action have changed the character of (4)_____ white universities; now about 13 percent of all undergraduates are black or Latino. (5)_____ a recent study by the Century Foundation found that at the nation's 146 most (6)_____ schools, 74 percent of students came from upper middle-class and wealthy families, while only about 5 percent came from families with an annual income of (7)_____ $35,000 or less.

Many schools say diversity—racial, economic and geographic—is (8)_____ to maintaining intellectually (9)_____ campuses. But Richard Kahlenberg of the Century Foundation says that even though colleges (10)_____ they want poor kids, "they don't try very hard to find them (11)_____ rural students, many colleges don't try at all. "Unfortunately, we go where we can (12)_____ a sizable number of potential applicants," says Tulane admissions chief Richard Whiteside, who (13)_____ aggressively—and in person—from metropolitan areas. Kids in rural areas get a glossy (14)_____ in the mail.

Even when poor rural students have the (15) for top colleges, their high schools often don't know how to get them there. Admissions officers (16)_____ guidance counselors to direct them to promising prospects. In (17)_____ high schools, guidance counselors often have personal (18)_____ with both kids and admissions officers. In rural areas, a teacher, a counselor or (19)_____ an alumnus "can help put a rural student on our radar screen," says Wesleyan admissions dean Nancy Meislahn. But poor rural schools rarely have college (20)_____ with those connections; without them, admission "can be a crapshoot," says Carnegie Mellon's Steidel.

A．promises

B．tries

C．works

D．manages

es, families, jobs, and social customs.