—Sorry, I ____. I have many things to do.
A:mustn't
B:can't
C:needn't
D:won't
切西瓜时,会流出一些汁液,这些汁液是从细胞的哪部分流出来的?( )
读图,回答
下列农业生产的做法符合因地制宜、可持续发展的是( )