若集合A={x|-x2+4x-3＜0},则A等于（ ）A.{x|1＜x＜3} B.{x|x＜1或x＞3}C.{x|1≤x≤3}
常温下，在水电离出的c(H+)＝10－14mol/L的溶液中，一定能大量共存的（ ） A．K+、Na＋、HCO3－、Cl－ B．K＋、Br-、AlO2－
读下图，回答下面2题。 16．A、B、C分别代表 A．商业区、住宅区、工业区 B．工业区、商业区、住宅区 C．商业区、工业区、住宅区
Everyone tries to get to school on time. But when bad weather gives you trouble（麻烦）, can you still make it before the bell rings? In northern China during spring, big sandstorms（沙尘暴
“When did you leave the farm?” “____ the end of last year.” A. In B. By C. At D. Since
