若一个多边形的内角和等于1080°,则这个多边形的边数是( )
A:9
B:8
C:7
D:6
从下列物质的结构层次看,由简单到复杂的顺序是 ( )
根据句意及汉语提示完成单词
①There's a____(电脑)on the teacher's desk.
② What can you see in the____(图片)?
③ Is there a____(电视)in Lucy's room?
④There isn't any ____(家具)in the old house.
⑤The old man is ____(九十)years old.
关于自然界的水循环,下列说法中正确的是( )