Matthew listened with full attention in chemistry lesson, _____to miss any point from the teacher.

 [ ]

A. not trying

B. trying not

C. to try not

D. not to try

对霍乱疫点，在传染源隔离后，如无粪便检验条件，自疫情处理后几日内无新病例出现，亦可解除。（）

A.3

B.5

C.7

D.10