单项选择题
A complete investigation into the causes of the acciden...
单项选择题A complete investigation into the causes of the accident should lead to improved standards and should______new operating procedures.
Not having made adequate preparations, they thought it ...
单项选择题Not having made adequate preparations, they thought it better to______the excursion till next week.
Users must never give their password to ______over the ...
单项选择题Users must never give their password to ______over the computer network, no matter how official the request appears.
