A:两样东西一共多少元?
B:书包比计算器贵多少元?
C:两样东西相差多少元?
D:书包比计算器便宜多少元?
____ (talk) with your parents often is a good way to make them understand you.
看到三个面。
抛物线y=x2-4x-7的顶点坐标是( )
如图所示的体温计最小刻度为 ____ ℃,此时它的示数为 ____ ℃;