题目

The earliest maps were probably drawn in the Middle East . Some of these maps have ______ and they show us the people at that time thought the earth flat (平的) . As time went by , the pictures became more detailed and maps were more ________ made . Later on , ancient Greeks(希腊人) used their ________ of math and science to make maps . Greek maps tell us the Greeks knew the world was ________ .From simple pictures , mapmaking has turned into a science . Maps are made ________ surveying(勘测) land . In the 1900s , people around the world started to share information to make __________ m如图是甲、乙两物质的溶解度曲线．下列说法正确的是（ ） A.甲、乙两物质的溶解度相等B.甲、乙两物质的溶解度均随温度升高而增大C.常用降温法从甲的饱和溶液中获取甲的晶体D.将乙的饱和溶液温度由t2℃降至0℃，有晶体析出