Some companies use hidden cameras in order to check up on their employees.有些公司用隐藏的摄像机来监视雇员。If you are not sure, you ought to check up on the facts.你如果没把握，就该去核对事实。Don't worry; no-one is going to check up on you.别担心，没人会监督你的。Dustin called me to check up on some facts.达斯廷打电话给我核实几项事实。