“Design of experiments” is a statistical method that helps ______ .

A) determine how various elements of a system interrelate
B) identify which factors may influence specific variables of a product or process
C) establish a standard by which to measure performance
D) compare actual or planned project practices to those of other projects

下面哪一种笔可以在恶劣环境下写出字迹？（）

A.碳素笔

B.圆珠笔

C.钢笔

D.铅笔