题目

Zheng Lin is a Junior 3 student in Shijiazhuang, Hebei. Earlier this month, Zheng and his classmates stood on the street with a box asking people for donations(捐款).Later they gave the money they got to the poor students in their school.     Many Chinese students raise money to help people in need. Most of the time, they hold a box and ask for donations on the street or in the park. Or they sell things like old books and CDs. Those students have done a great job so far. The money helps the students in poor areas like Yunnan and Gansu with new clothes, pens and pencils.     Teena下表是四种植物根尖分生组织细胞的细胞周期，在选择用于观察有丝分裂过程的实验材料时，最好选用植物细胞周期的时间(h)a时间b时间合计物种110. 60.411物种2180.518.5物种316. 5218.5物种410.42.312.7A.物种1B.物种2C.物种3D.物种4