用所学单词自编两个句子。
例如:I can draw, I can draw, I can draw a flower.
I can read, I can read, I can read a book.
I can sing, I can sing, I can sing a song.
a和b都是自然数,已知 a×79=b÷79 ,则 b>a 。
列举聚落形成与发展的有利条件____、____、____、____、____等。