主动运输
参考答案：
指细胞通过某种耗能过程，将物质由膜的低浓度侧向高浓度侧转运的过程。
玉米根尖分生区细胞会不停地分裂生长。此时这些细胞[ ]
A．两组中心粒会分别移向两极
B．有K+穿过原生质层进入大液泡
C．染色体数目不断减少
D．保持着全能性
句型转换。
1. My mother does the housework at home every day. (否定句)
My mother _________ ________ the housework at home every day.
2. Millie often goes to visit her grandparents by bus. (对画线部分提问)
_______ ________ Mille go to visit her grandparents?
3. Some of my friends do well in English. (同义句)
Some of my friends ____________ __________ ________ English.
4. They like Miss Zhang best. (同义句)
______ ______ teacher is Miss Zhang.
5. They usually celebrate Halloween by having a special party. (对画线部分提问)
_______ ______ they usually celebrate Halloween?
having a special party. (对画线部分提问)