Sugarnaturally in fruit so eating fruit can add to the contents of sugar inside our body.

问题补充：

Sugarnaturally in fruit, so eating fruit can add to the contents of sugar inside our body.

A. happens

B. occurs

C. appears

D. forms

答案：

A. happens

(答案→)B. occurs

C. appears

D. forms

解析：occur此处意思为“存在于；出现在”，句意：水果天然含糖分,因此多吃水果能够增加体内糖分的含量。