单项选择题
Sign up for alerts（）your mobile phone or email.
A.to send to B.to be sent to C.to be sent D.to sent to
单项选择题 Don’t（）secure websites using public Wi-Fi.
单项选择题 （）conduct a background check on the company, making as many phone calls and Internet searches as you can.
单项选择题 Use the（）version of your web browser.
