Mr.Li often drives his car to work,but he rides a bike there.
A:usually
B:sometimes
C:always
D:often
某碳酸钠样品中混有少量氯化钠,根据如图所示信息完成相关计算。
(反应的化学方程式为:CaCl2+Na2CO3=CaCO3↓+2NaCl)
设实数x,y满足条件4x-y-10≤0x-2y+8≥0x≥0,y≥0,若目标函数z=ax+bya>0,b>0的最大值为12,则2a+3b的最小值为( )