原子质量数等于原子的（）。
A.核电荷数和电子数之和
B.中子数和电子数之和
C.质子数和中子数之和
参考答案：C
读一读，重新排顺序。
( ) All right. We clean the desks and chairs.
( ) Good morning. Let's clean the classroom.
( ) Wow! It's nice and clean. Good job.
( ) Let's clean the desks and chairs.
( ) Good idea.
简述资本主义工资的本质和形式？
