The huge explosion at Krakatau was the result of two different factors．One was that the volcano had not broken out for some time and so at the very center of the volcano there was a huge plug of lav
The activity is called saving the earth which refers to more reduction of ____ caused to the world by freon (氟里昂)of refrigerators. A. hurt B. harm C. destroy
．右图是中国近代一张火柴的商标。其设计最能反映