Beethoven is a very____ (著名的)musician .I'm____ (紧张的)out because I can't find the way home.My mother often____ (担心)about my father's health..She likes to s____ e-mails at school.Lily is very t____ , she'd like to have some water.
圆内接正六边形的边心距为23,则这个正六边形的面积为 ____cm2.
有历史学家感慨:“为什么工业化浪潮不是在法国之后穿过地中海而席卷突尼斯、阿尔及利亚呢?是地中海太宽阔了吗?果真如此,那么为什么又能横渡大西洋而在北美生根开花?”这主要说明( )