由于栅格单元中存在多种地物，而数据中常常只记录一个属性值，这会导致属性误差。所以在决定栅格代码时尽量保持地表的真实性，保证最大的信息容量 。
A. 对
B. 错
矢量结构通过记录坐标的方式来表示点、线、面地理实体
A. 对
B. 错
Busy________ she is,Rita________ two hours every Sunday afternoon to spend with her son.
A. though; sets out
B. as; sets aside
C. as; sets down
D. though; sets off
Ten years later I still keep in touch with my classmates ________ I've never met them.
A. now that
B. so that
C. even though
D. in case
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