In order to keep your computer protected at all times, you need to_____________.
A. Check that your computer has a firewall enabled.
B. Keep your anti-virus software up to date.
C. Use a wireless password that is easy to guess.
D. Never open attatchments from sources that you don't trust.
To buy from good guys, you need to ________________________.
A. make sure they've got good feedback from others
B. keep a copy of your order confirmation
C. look for the padlock symbol in the browser frame
D. talk with the seller through telephone or email if necessary
春季对应八卦的卦,夏季对应于八卦的卦,秋季对应于八卦的卦,冬季对应于八卦的卦。