All I could hear was the discreet __________ of our new air conditioner. Unnerved, I walked over to my desk and turned on my computer.

As soon as we walked into the house, we turned on the air conditioner. B.

I looked all over the house for the letter ______ and it turned out to be in my pocket.

A、always
B、all the time
C、altogether
D、also

I am afraid I have got a ______ about the mistakes of the faulty installation of my air conditioner.

A、complain
B、complaint

After I put down my newspaper, I walked over to the window and looked out. ________________________,