单选题设n(n≥3)阶矩阵若矩阵A的秩为n-1，则a必为______A．1．B．C．-1．D．

单选题设函数g(x)可微，h(x)=e 1+g(x) ，h"(1)=1，g"(1)=2，则g(1)等于

单选题设x＞0处f(x)连续且严格单调增，并设，则F(x)在x＞0处()．

单选题设f(x，y)与ψ(x，y)均为可微函数，且ψ'y(x，y)≠0，已知(x0，y0)是f(x，y)在约束条件ψ(x，y)=0下有一个极值点，下列选项正确的是

单选题设A为m阶方阵，B为n阶方阵，，则|C|等于______

单选题设f(x)在x=a处可导，则等于

单选题曲线y=x2与所围成的图形绕x轴旋转一周的旋转体的体积为( )

单选题If the opinion polls are to be believed, most Americans are coming to trust their government more than they used to. The habit has not yet spread widely among American Indians, who suspect an organization which has so often patronized them, lied to them and defrauded them. But the Indians may soon win a victory in a legal battle that epitomizes those abuses. Elouise Cobell, a banker who also happens to be a member of the Blackfeet tribe in Montana, is the leading plaintiff in a massive class-action suit against the government. At issue is up to $10 billion in trust payments owed to some 500,000 Indians. The suit revolves around Individual Indian Money (11M) accounts that are administered by the Interior Department's Bureau of Indian Affairs (BIA). Back in the 1880s, the government divided more than 11m acres of tribal land into parcels of 80 to 160 acres that were assigned to individual Indians. Because these parcels were rarely occupied by their new owners, the government assumed responsibility for managing them. As the Indians' trustee, it leased the land out for grazing, logging, mining and oil drilling--but it was supposed to distribute the royalties to the Indian owners. In fact, officials admit that royalties have been lost or stolen. Records were destroyed, and the government lost track of which Indians owned what land. The plaintiffs say that money is owing to 500,000 Indians, but even the government accepts a figure of about 300,000. For years, Cobell heard Indians complain of not getting payment from the government for the oil-drilling and ranching leases on their land. But nothing much got done. She returned to Washington and, after a brush-off from government lawyers, filed the suit. Gale Norton, George Bush's interior secretary was charged with contempt in November because her department had failed to fix the problem. In December, Judge Lam berth ordered the interior Department to shut down all its computers for ten weeks because trust-fund records were vulnerable to hackers. The system was partly restored last month and payments to some Indians, which had been interrupted l resumed. And that is not the end of it. Ms Norton has proposed the creation of a new Bureau of Indian Trust Management, separate from the BIA. Indians are cross that she suggested this without consulting them. Some want the trust funds to be placed in receivership, under a , neutral supervisor. Others have called for Congress to establish an independent commission, including Indians, to draw up a plan for reforming the whole system. A messy injustice may at last be getting sorted out.

单选题已知函数f(x，y)在点(0，0)某邻域内连续，且，则