A:该元素属于金属元素
B:该原子的相对原子质量为47.87
C:该原子在化学变化中容易失去电子
D:该原子的质量由构成其原子的质子和电子决定
经过点A(1,2),并且在两坐标轴上的截距的绝对值相等的直线共有( )
选出合适的应答语。
A. You should go to bed early.
B. You should wear a sweater.
C. She should tell the teacher and go to see the doctor.
D. You should tell your mother.
E. You should take it to see the vet.
F. You should help her do some chores.
方程x+y+3z=22的正整数解的组数是____ .