利用地理信息技术可以快速获取顺义至人民大学的乘车方案,以及准确的票价和时间信息。下图信息的获取过程为( )
①全球定位系统确定起止点的位置
②遥感技术监测有几条可选路径
③地理信息系统获取路网信息,选择最佳路径
④数字地球计算全程所用时间
A:①③
B:②③
C:②④
D:①②③④
我国是世界上河流众多的国家,有许多源远流长的大江巨川,读长江水系图。
某校实行学案式教学,需印制若干份数学学案,印刷厂有甲、乙两种收费方式,除按印数收取印刷费外,甲种方式还需收取制版费而乙种不需要.两种印刷方式的费用y(元)与印刷份数x(份)之间的关系如图所示:
(1)填空:甲种收费的函数关系式.
乙种收费的函数关系式.
(2)该校某年级每次需印制100~450(含100和450)份学案,选择哪种印刷方式较合算?
This boy is Peter .He is from America.He is ten years old . His hair is yellow.Peter can play basketball. This is his school.It's very big. There are forty students in his class. Miss White is his English teacher. Peter is good at English.