常温时,在pH=13的无色透明溶液中一定能大量共存的一组离子是( ) A.Na+、SiO32﹣、NO3﹣、CO32﹣ B.K+、Cl﹣、MnO4﹣、SO42﹣ C.Na+、NO3﹣、SO42﹣、
零上13℃记作+13℃,零下2℃可记作( ) A.2 B.-2 C.2℃ D.-2℃
完形填空Henry is a little boy. He is always 1 to others. So he has a lot of friends. Tomorrow is Henry’s birthday. His friends Mike and Betty decide 2 him a present. They are tal
下列各组线段(单位:㎝)中,成比例线段的是( ) A.1、2、3、4 B.1、2、2、4 C.3、5、9、13 D.1
在下列基因组合中,表现出相同性状的是 ( )A.Cc和CC B.CC和cc C.Cc和DD D.Cc和cc
It is often said that the joy of traveling is _____ in arriving at your destination _____ in the journey itself. A. 不填;but B. 不填;or C. not; or
某企业生产的产品很受市场欢迎,每月生产的产品总能当月脱销。该企业本月的销售收入比上一个月翻了一番,在其他情况不变的情况下其原因可能包