What can we infer from this discussion

A．That Bob does not get along with his lab partner.

B．That the students performed the experiment correctly.

C．That the students had problems, and could not complete the lab experiment.

D．That there was a fire in the lab during the experiment.

电脑的主机箱内一般都包括了（）

A.CPU、存储器和显示器

B.主板和外设

C.扫描仪和CPU

D.主板和CPU