1, the following four functions, in the same quadrant, when x increases, the function of y value decreases is ().

a、y=5x B、C、y=3x+2 D，

2. Among the following four groups of line segments, the group that does not constitute a proportional line segment is ().

a、 1cm、2cm、3cm、6cm B、2cm、3cm、4cm、6cm、

c、 1cm、cm、cm、cm、D、 1cm、2cm、3cm、4cm、

3. The positive integer solution of inequality is ()

A.2 B.3 C.4 D.5

4. The solution set of inequality group is ()

A.≤x≤4 B.