. Many experts agree that once these treasures are _______ to the air, great harm will be done to them. So they think it better not to unearth the treasures.

A．exposed

B．threatened

C．constructed

D．conserved

老年人用药时需做血药浓度监测的药物是

A．肾上腺素
B．消心痛
C．阿司匹林
D．利多卡因
E．链霉素