单选题如下图所示，AB∥CD，若∠ABE=120°，∠DCE=35°，则∠BEC=______

单选题设函数f(x)在x=x 0 处存在三阶导数，且f"(x 0 )=0，f"(x 0 )=0，f"""(x 0 )=a＞0，则

单选题Twenty-seven years ago, Egypt revised its secular constitution to enshrine Muslim sharia as "the principal source of legislation". To most citizens, most of the time, that seeming contradiction-between secularism and religion-has not made much difference. Nine in ten Egyptians are Sunni Muslims and expect Islam to govern such things as marriage, divorce and inheritance. Nearly all the rest profess Christianity or Judaism, faiths recognised and protected in Islam. But to the small minority who embrace other faiths, or who have tried to leave Islam, it has, until lately, made an increasingly troubling difference. Members of Egypt's 2,000-strong Bahai community, for instance, have found they cannot state their religion on the national identity cards that all Egyptians are obliged to produce to secure such things as driver's licenses, bank accounts, social insurance and state schooling. Hundreds of Coptic Christians who have converted to Islam, often to escape the Orthodox sect's ban on divorce, find they cannot revert to their original faith. In some cases, children raised as Christians have discovered that, because a divorced parent converted to Islam, they too have become officially Muslim, and cannot claim otherwise. Such restrictions on religious freedom are not directly a product of sharia, say human- rights campaigners, but rather of rigid interpretations of Islamic law by over-zealous officials. In their strict view, Bahai belief cannot be recognised as a legitimate faith, since it arose in the 19th century, long after Islam staked its claim to be the final revelation in a chain of prophecies beginning with Adam. Likewise, they brand any attempt to leave Islam, whatever the circumstances, as a form of apostasy, punishable by death. But such views have lately been challenged. Last year Ali Gomaa, the Grand Mufti, who is the government's highest religious adviser, declared that nowhere in Islam's sacred texts did it say that apostasy need be punished in the present rather than by God in the afterlife. In the past month, Egyptian courts have issued two rulings that, while restricted in scope, should ease some bothersome strictures. Bahais may now leave the space for religion on their identity cards blank. Twelve former Christians won a lawsuit and may now return to their original faith, on condition that their identity documents note their previous adherence to Islam. Small steps, perhaps, but they point the way towards freedom of choice and citizenship based on equal rights rather than membership of a privileged religion.

单选题设f"(x)在x=0处连续，且则

单选题一个正偶数的算术平方根是口，那么与这个正偶数相邻的下一个正偶数的算术平方根是( )。

单选题设，则f(x，y)等于______A．B．C．D．

单选题下列极限______不正确．A．B．C．D．

单选题设离散型随机变量X的分布列为 X 0　1　2 P 0.4　c　2c 则c= A.0.1 B.0.2 C.0.3 D.0.4

单选题f(x)有一个原函数则∫f"(x)dx=______A．-cosx+CB．C．D．无法计算

单选题一个充气的救生圈的大部分水平放在一张桌子上，一只蚂蚁沿半径为33厘米的救生圈上最高的圆周爬行，另一个蚂蚁沿垂直桌子的半径为9厘米的圆周爬行。他们同时从同一点出发，爬行速度相同，问小圆上的蚂蚁第一次碰上大圆的蚂蚁时爬行了______

单选题以下说法正确的是( )．

单选题设四阶方阵A=[α1，α2，α3，α4]，B=[α4，α3，α2，α1]，其中α1，α2，α3，α4均为4维列向量，A可逆，且|A|=1，又设则B*等于()

单选题设函数f(x)有二阶导数，且,则(A)f(0)是f(x)的极大值．(B)f(0)是f(x)的极小值．(C)(0，f(0))是曲线y=f(x)的拐点．(D)f(0)不是，(x)的极值，(0，f(0))也不是曲线y=f(x)的拐点．

单选题设A是m×n矩阵，B是n×m矩阵，且n＞m，则必有