题目

The United States seems to have become extremely enthusiastic about competition. The famous Scripps National Spelling Bee — an annual spelling contest — now allows kids who lost in regional competitions but whose parents agree to pay an entry fee along with their own food and accommodation to compete. And while some kids are working for what they call a “spelling career”, others are approaching chess competitions, dance competitions, cooking or other passions (爱好) that previous generations developed somewhat later in life.I’m disturbed by the phenomenon, which seems to be getting如图表示细胞的有关生理过程．其中，过程②表示细胞的（ ）A．分裂B．生长C．分化D．流动