Zhang Guorong, a HK pop singer, jumped from the top of a building and killed himself. That is because he had been fed up with living in the world.老師，這里because引導的表語從句是過去完成時，而主句that is ..卻是一般現在時，這樣對嗎？是不是應該改為that was呢？期盼老師的解答。