Spyware and other forms of malware are the biggest online threat to your computer’s（）nowadays. These malicious（）which get to your PC through freeware, shareware, commercial sites, deceptive pop-ups or in any other way, can record your surfing habits and sites you visit, share your personal information with their partners. Any personal（）, when in wrong hands, can leave you a victim of an "identity theft" by stealing your credit（）details, birth records and other（）information.

birth records and other（）information.

A．public

B．confidential

C．open

D．commercial

下面关于空心板的说法中，正确的是（）。

A、空心板应在两端堵孔

B、三面搁置有利于空心板受力

C、三面搁置易使楼面产生裂缝

D、空心板搁置在砖墙上时先应坐浆