Simon thought his computer was broken _______ his little brother pointed out that he had forgotten to turn it on.

A．until

B．since

C．after

D．because

口腔科每年都有新职工参加工作，科主任和护士长都会提到要做好个人防护的措施是

A．对高危人群特殊对待
B．高度的无菌观念
C．使用一次性器械和材料
D．严格消毒措施
E．定时注射免疫疫苗