单选题已知f(x)=3x2+kx-3(k＞0)，当x＞0时，总有f(x)≥20成立，则参数k的最小取值是( )． (A) 32 (B) 64 (C) 72 (D) 96

单选题The semantic ______ of ancient documents is not unique. Even in our own time, many documents are difficult to decipher. A. aspect B. pattern C. opacity D. intention

单选题已知c为实数，二次方程x2+x+c=0有两个复数根x1和x2，满足|x1-x2|=3，则c=()。

单选题设函数f(x)在区间(a，b)内有二阶导数，且f"(x)＜0，则f(x)在(a，b)内{{U}} {{/U}}。 A.单调减少 B.单调增加 C.先单调增加，然后单调减少 D.上述A、B、C都有可能

单选题设an为等差数列，且a3+a7+a11+a15=200，S17的值为______。 A．580 B．240 C．850 D．200

单选题若f(x)，g(x)均为奇函数，那么函数f[g(x)]为______。 A．奇函数 B．偶函数 C．非奇非偶函数 D．既是奇函数又是偶函数

单选题如下图所示，三角形ACD，三角形BDE都是等腰直角三角形．5BC=CD

单选题直线l与直线2x-y=1关于直线x+y=0对称，则直线l的方程是______。 A．x-2y=1 B．x+2y=1 C．2x+y=1 D．2x-y=1

单选题{{B}}Directions:{{/B}} There are 15 questions in this part of the test. Read the passage through. Then, go back and choose one suitable word or phrase marked A, B, C or D for each blank in the passage. Mark the corresponding letter of the word or phrase you have chosen with a single bar across the square brackets on your Machine-scoring Answer Sheet. Acid rain leads to fish mortality. Many species of fish cannot survive in aquatic environments where the pH is below 5.0. If the water is too acid, the gill systems of many kinds of fish can be damaged.{{U}} {{U}} 1 {{/U}} {{/U}}, the acid alters the blood chemistry of all fish. As a result, the fish population in an acidic environment decreases{{U}} {{U}} 2 {{/U}} {{/U}}becomes extinct.Approximately 20 percent of the lakes in Scandinavia are without fish. Moreover, in Nova Scotia the{{U}} {{U}} 3 {{/U}} {{/U}}salmon industry may be threatened by the decrease of salmon in rivers and streams. The impact is also{{U}} {{U}} 4 {{/U}} {{/U}}in the waters of Ontario and Quebec, where fish populations are (25) the decline. What potential remedies exist for the acid rain{{U}} {{U}} 5 {{/U}} {{/U}}? The experts disagree. Some say new environmental laws should be{{U}} {{U}} 6 {{/U}} {{/U}}to control the emission of pollutants in the atmosphere. Some say that if we had known how serious acid rain was, we would have planned{{U}} {{U}} 7 {{/U}} {{/U}}to prevent it.{{U}} {{U}} 8 {{/U}} {{/U}}, all agree that if the consumption of fossil fuel were reduced, we would have less of a problem. Another{{U}} {{U}} 9 {{/U}} {{/U}}is that special scrubbers could be installed in smokestacks to remove a good{{U}} {{U}} 10 {{/U}} {{/U}}of the pollutants before they get into the atmosphere. Other ideas even include breeding more{{U}} {{U}} 11 {{/U}} {{/U}}fish. And research suggests that spreading lime into lakes may be effective in{{U}} {{U}} 12 {{/U}} {{/U}}acidity. In conclusion, it is clear that if we truly want to reduce the impact of acid rain, a{{U}} {{U}} 13 {{/U}} {{/U}}of remedies and international cooperation must be explored. It is a sad fact that acid rain probably could have been avoided if we{{U}} {{U}} 14 {{/U}} {{/U}}what we know now.

单选题某厂加工一批零件，甲车间加工这批零件的20%，乙车间加工剩下的25%，丙车间加工再余下的40%，还剩3600个零件没有加工，这批零件一共有{{U}} {{/U}}． A. 9000个 B. 9500 C. 9800个 D. 10000个

单选题方程所表示的曲线是()．A．圆B．椭圆C．抛物线D．双曲线

单选题甲、乙两地相距96km，P，Q两辆车同时从甲地出发匀速驶往乙地，开车1h后，P车在Q车前方12km处，P车比Q车早40min到达乙地，P车的行车速度是( )km/h。 (A) 12 (B) 24 (C) 36 (D) 48

单选题随着国民经济持续增长，我国的铁路运输进行了六次提速．已知北京至广州的路程2208km，第六次提速后的速度比第五次提速后的速度增加20%，时间却少用了2h．第六次提速后的速度为{{U}} {{/U}}． A. 184 B. 200 C. 220.8 D. 225

单选题已知点M(a，b)与点N关于x轴对称，点P与点N关于y轴对称，点Q与点P关于直线x+y=0对称，则点Q的坐标为______．

单选题Every society has its own peculiar customs and ______ of acting. A. ways B. attitudes C. behavior D. means

单选题设α1=(1，0，5，2)T，α2=(3，-2，3，-4)T，α3=(-1，1，a，3)T线性相关，则a=______。 A．1 B．2 C．4 D．5