During the long summer holidays, it is a _______ for American children to spend several weeks at summer camps.
A:costume
B:custom
C:customer
D:feast
如图,已知△ABC的顶点A,B,C的坐标分别是A(﹣1,﹣1),B(﹣4,﹣3),C(﹣4,﹣1).
____不,它是个黑色的枕头。(翻译句子)
分析右图,对生长素分布、运输、生理作用等不科学的解释是( )