调节阀口径的确定应包括的内容是（）和开度及可调比的验算。 A.工艺参数的确定 B.K

    Scientists think that a weather pattern( 形式)calledE1 Nino( 厄尔尼诺现象)caused the drought( 干旱)in Australia. E1 Nino causes different weather in different parts of the world. It causes a lot of rain and  floods in some places. It causes droughts in other places. Droughts can badly affect people and the land.    Ill Nino lasts about a year.    

    In normal weather conditions, warm winds from South America blow from east to west across the        Pacific Ocean. The winds early storms to Australia. These storms bring rain to Australia.   

    During an El Nino weather pattern the winds change direction. They blow from west to east across the Pacific Ocean. The storms no longer move across Australia. So Australia gets very little rain during El      Nino.  

    The drought began in January , 1982. El Nino often Occurs at this time of year. But that year , El         Nino was stronger than usual. There was very little rainfall(降雨量) in eastern Australia. There was also very little water in the rivers. The drought was at its worst in February ,1983 . At that time , the weather     was very hot. The forests and fields were very dry. Cotton growers couldn't plant their cotton. Sheep        farmers had no grass for their animals to eat. So many of them died. Because the forests were dry. forest   fires started quickly. Some of the fires burned for a month. Many forests were destroyed. Over 2 , 000    people lost their houses in the fires and 75 people died.  

    The Australian drought ofl982-1983 affected thousands of people and animals. The drought cost           the country over $ 3，000，000，000. It was a reminder(提示)to Australians of how the weather could change their lives.