Choose the correct variant1. one of many telephone lines connected to a central system in a large building, which all have different numbers Blank 1 Hold on, please.dial toneextensionhang up the phonepound keyI think I have the wrong number.Call me back, please. 2. the sound you hear when you pick up the telephone that lets you know that you can make a call Blank 2 Hold on, please.dial toneextensionhang up the phonepound keyI think I have the wrong number.Call me back, please. 3. the button on a telephone that has the symbol (#) on it Blank 3 Hold on, please.dial toneextensionhang up the phonepound keyI think I have the wrong number.Call me back, please. 4. When you call somebody by mistake you say Blank 4 Hold on, please.dial toneextensionhang up the phonepound keyI think I have the wrong number.Call me back, please. 5. When you want somebody to return your call you say Blank 5 Hold on, please.dial toneextensionhang up the phonepound keyI think I have the wrong number.Call me back, please. 6. When you finish the telephone conversation you Blank 6 Hold on, please.dial toneextensionhang up the phonepound keyI think I have the wrong number.Call me back, please. 7. When you ask somebody on the phone to wait until the person they want to talk to is available you say Blank 7 Hold on, please.dial toneextensionhang up the phonepound keyI think I have the wrong number.Call me back, please.