We all know that we ________ our carbon footprint, but I suspect that many people wouldn't be prepared to go as far as Joan Pick, a retired scientist living in south London.

 ---- Where are you going for the weekend?---- I haven’t decided yet. I _______ go fishing with my friends. 

―Must I report the situation of the new company to the manager now? ―No, you         . You are tired and you can do it after you have a good rest.

It is required that under no circumstances ______ betray ourselves even if there are temptations like money or beauty.

Delta, the American airline, is sometimes jokingly explained “Don’t expect your luggage to arrive” because it ______ be very slow.