There are many places of interest in China and it has many beautiful cities. So    visitors come here every year. In winter, about      visitors come to the north of China to feel the taste of the ice and snow.

A. millions of, ten thousands

B. millions of ,ten thousand

C. ten million, millions of

下图是绿色植物新陈代谢的图解，请根据图解回答问题：

在⑤过程中，C3接受[⑶]（）和[⑷]（），在酶等作用下，最后产生C₆H₁₂O₆等有机物，光合作用的总反应式是（）。