A:观察法
B:调查法
C:分类法
D:实验法
— Mike _______ a job in a bank, but to our surprise, he didn't take it.
— Maybe he got another job.
若不等式组x≥0x+3y≥43x+y≤4所表示的平面区域被直线y=kx+43分为面积相等的两部分则k的值是( )