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 Call me back, please.pound keyextensionI think I have the wrong number.Hold on, please.hang up the phonedial tone 2. the sound you hear when you pick up the telephone that lets you know that you can make a call Blank 2 Call me back, please.pound keyextensionI think I have the wrong number.Hold on, please.hang up the phonedial tone 3. the button on a telephone that has the symbol (#) on it Blank 3 Call me back, please.pound keyextensionI think I have the wrong number.Hold on, please.hang up the phonedial tone 4. When you call somebody by mistake you say Blank 4 Call me back, please.pound keyextensionI think I have the wrong number.Hold on, please.hang up the phonedial tone 5. When you want somebody to return your call you say Blank 5 Call me back, please.pound keyextensionI think I have the wrong number.Hold on, please.hang up the phonedial tone 6. When you finish the telephone conversation you Blank 6 Call me back, please.pound keyextensionI think I have the wrong number.Hold on, please.hang up the phonedial tone 7. When you ask somebody on the phone to wait until the person they want to talk to is available you say Blank 7 Call me back, please.pound keyextensionI think I have the wrong number.Hold on, please.hang up the phonedial tone