[单选题](144)在精馏塔内，液相负荷的大小是通过调整( )来实现的，它也是实际操作中实现正常操作的主要手段。
A.进料状态
B.蒸馏釜和冷凝器中载热体的流量
C.回流比
D.精馏釜的温度

In an ideal world, the nation’s elite schools would enroll the most qualified students. But 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, "
A. excellent
B. wealthy
C. popular
D. competitive

Two powerful car bombs have exploded in a crowded part of San Salvador. Two boys were injured, one of them seriously when he was hurled across the street by the force of the explosion. Shooting is reported to have broken out shortly afterwards. No one has claimed responsibility for planting the bombs, but eyewitnesses say the car had been left there by two women. A correspondent for the BBC in San Salvador says the incident is bound to heighten tension in the run-up to next week’s election to National Assembly. Some hours earlier there were violent street disturbances in San Salvador when hundreds of demonstrators protested against the detention of a leading trade unionist Mr. Wudato Santallo.