（1）、I'll turn his invitation and stop him from going swimming in the river.
（2）、Could you please turn the computer? I need to send an email.
（3）、The school's pretty strict about phones - of course you can bring them, but you have to turn the phones and keep them in a place as you are required before class.
（4）、The tape player is not loud enough, and we can't hear clearly. Please turn it .
