1. Rectangular length/cm 1 1 10 9 8 7

Rectangular width/cm 1 2 3 4 5

2. Length of rectangle/cm 24 12 8 6

Rectangular width/cm 1 2 3 4

Two.

Only three interplanting sets, only one interplanting set, only two interplanting sets, only three interplanting sets.

1 possibility, 3 possibilities, 6 possibilities and 10 possibility.

A: There are 20 different possibilities.

Three.

Blue, blue, blue, blue, black, blue, black, black, black.

A: There are four possibilities.

Four.

five

five

A: On March 3 1 day, I also went to the nursing home to take part in voluntary labor.