(1) chromosomes are easily stained with alkaline dyes, such as magenta acetate (gentian violet, modified phenol magenta). In the visual field, the centromere of cell A divides, the chromatid divides, and the number of chromosomes doubles. This cell is in the late stage. In statistics, we should pay attention to taking multiple samples from each group and observing multiple fields of vision from each film, so as to observe more comprehensively. According to the histogram, the treatment at 2℃ is 10.

(2) In order to explore the killing effect of paclitaxel combined with allicin on cancer cells, the independent variable is whether paclitaxel and allicin exist, and some control experiments can be designed. The control group was added with optional materials and reagents A+B, while the other groups were A+B+D? A+B+E, A+B+D+E. Before cell counting, it is necessary to shake the cell culture solution evenly to ensure accurate counting.

So the answer is:

(1)① magenta acetate (gentian violet, modified phenol magenta)? ② In the later stage, multiple samples were taken from each group, and multiple visual fields were observed in each film. Treated at 2℃ for 65438±02h.

(2)①A+B+D？ A+B+E、A+B+D+E？ (2) shake well.