如图，A，B，C是⊙O上的三点，BE切⊙O于点B， D是与⊙O的交点.若，则______；若，，则 .
Just like the young character in Hannah Montana, who so often fights with her father over her desire to be more independent, British teenagers also have their troubles. A recent survey among 2,000 Bri
如图，C是以AB为直径的⊙O上一点，已知AB=5，BC=3，则圆心O到弦BC的距离是_ _________．
发育的整个过程的起点是： A 受精卵 B 胎儿 C 婴儿 D 卵细胞
西周初年，疆域空前辽阔。周王为巩固对周边的统治，“封建亲戚，以藩屏周”。这是下面的哪一种制度？( ) A．禅让制 B．世袭制
A study published in September suggests there is a surprising way to get people to avoid unhealthy foods; change their memories. Scientist Elizabeth Loftus of the University of California at I rvine a
The newly built washingroom in the railway station is to the disabled passengers. A.perfect B.accessible C.remarkable D.potential
主张掌握自然规律，然后利用它为我所用的思想家是( ) A．荀子 B．庄子 C．孟子 D．韩非子
，集合
，则
