If it ______ tomorrow, our picnic _______ to be put off. [ ]

A. rains; would have  

B.. rains; has    

C. should rain; would have  

D. would rain; would have

“密封发酵法”进行粪便无害化处理时，杀死病原菌与寄生虫卵的主要因素是（ ）。

A．高温

B．缺氧

C．氨气

D．缺乏营养物质

E．生物拮抗