1. For Mrs. Cox, like most of the students in her school, is Black.
    这是因为科克斯夫人和学校大多数学生一样是黑人。

2. From June to September the Nile rises and submerges the whole valley; then in the beginning of October it begins to fall, leaving the land saturated with water and covered with a layer of rich, black soil.
    从六月到九月，河水暴涨，淹没了整个流域；到十月初，河水开始减退，剩下饱含大量水分的土地，还覆盖着一层肥沃的黑土。