下列工业部门中，珠江三角洲比较发达的是（   ）

已知|a﹣1|=4，|2﹣b|=5，求a﹣b的值．

根据句意和首字母提示完成下列句子。
There are sixty m____  in an hour．
He is ill, and his i____  makes us feel sad．
A lot of t____  are visiting the Great Wall, so it is very crowded．
Good food and e____  help me to study better．
It is n____ to eat a balanced diet.