计算-2013+2013的结果是( )
A:4026
B:-4026
C:0
D:1
实验室中金属钠保存在 ____
My students,________you have a heart loving life,you always can find things that would make you happy each day.
27+12____40 44-23____20 79-18____61
33+36 ____68 28-21____15 89-23____57
46-23 ____46-24 75+21____98-5