1.the old man… down the river now. are going is gone has gone is going 2.i… never… in an american school. is being are being have been will be 3.next year we … biology in science class. will be studying shall study were studying studied 4.mum … a birthday cake when natalie… came home. were baking, was come was baking, is coming was baking, came had baked, had come 5.everybody … a present for sandra on her birthday yesterday. gave has given will give is given 6.my best friend always… me postcards on holidays. had sent sends is sending are sending