49, It is too hot now. That’s why we consume a lot of energy. (if)
=> If it wasn't too hot then, we wouldn't consume a lot of energy
50, He takes part in all of his school activities. His health is poor. (despite)
=> Despite his poor health, he takes part in all of his school activities
51, I bought a new washing machine. It cost me a lot of money. (which)
=> I bought a new washing machine which cost me a lot of money
52, I didn’t have the key. I couldn’t get into the house. (because)
=> I couldn't get into the house because I didn't have the key