古人云:“橘生淮南则为橘,橘生淮北则为枳”这就是说,淮南的橘子移种到淮北就不甜美了,产生这一差异的主要原因是( )
A:土壤
B:空气
C:阳光
D:温度
It was only after he had read the papers ________ Mr. Gross realized the task before him was extremely difficult to complete.
广东省比较常见的气象灾害是( )
在热传递的过程中,传递____ 的多少叫热量,热量的单位是____