A．general pessimism aboutB．some doubt aboutC．different ……

单项选择题A．it helped him earn extra moneyB．his season was overC．he needed more experienceD．he could improve his skills

填空题returns

单项选择题A．24B．27C．18D．20

单项选择题A．make computer users aware of hackingB．train hacking expertsC．enlighten people on how to prevent computer attacksD．display the harms of hacking

单项选择题A．2B．3C．4D．5