掩码
参考答案：
屏蔽一种显示机密的信息的计算机技术。例如计算机终端上的密码或是报表。
— Would you go to the concert this evening?
— Sorry. ________ tomorrow's lessons, I have no time to go out with you.[ ]
A. Not preparing
B. Not having prepared
C. Not to prepare
D. Being not prepared
小明足部受伤发炎，医生在其左臂静脉滴注抗生素，药物到达足部的途径是
①左心房；②右心房；③右心室；④主动脉；⑤肺动脉；⑥肺静脉；⑦上腔静脉；⑧下腔静脉；⑨股动脉；⑩左心室 [ ]
A．①③④⑥②⑦⑧⑨⑩
B．⑦②③⑤⑥①⑩④⑨
C．⑦②③⑤⑥①⑧④⑨
D．⑦②③⑥⑤①⑩④⑨
