细胞数目增多是由于（ ）
A：细胞的分裂
B：细胞的分化
C：细胞的生长
D：细胞的分裂和生长
扩句
①鲜花盛开了。
②小华做操。
—The difficult maths problem has been solved by Tom at last.
— Indeed; and the ___ way Tom worked out the problem impressed the teacher deeply.
Are they going to____ (clean) their classroom?
