1.What (you/do).....were you doing..at this time yesterday ?
2.Poisonous gases (pump) ..are pumped......into the atmosphere every day.
3.I'm not used to (walk) .....walking... so far , no I must stop (rest)....to rest. for a while.
4. If we use energy-saving bulbs, we (save)…will save…… a lot of money
His joke made me(laugh).... laugh ...a lot.