--- Kangkang, could you tell me how to cook noodles?
--- OK. First, you should_______ham, cabbage and onions finely.
A:cut up
B:cut down
C:cut off
读下图,图为世界某区域图。④地经常发生洪涝灾害,其主要原因是( )
a÷b=2,a、b的最小公倍数是____?(a、b是不等于0的自然数)
说一说,下面的哪些图形是对称的?( )