如图表示“制作洋葱鳞片叶表皮细胞临时装片”实验的部分操作步骤,其正确的操作顺序是( )
A:①→②→③→④
B:③→④→②→①
C:①→②→④→③
D:④→③→①→②
Some countries would be ____ (flood) if sea level around the world rose.