【简答题】英译汉: In creating a lens a lens designer attempts to “trap” light by forcing all the rays arising英译汉: In creating a lens a lens designer attempts to “trap” light by forcing all the rays arising from a...
【简答题】今年夏天万州持续干旱,当天空乌云密布时,人们用飞机把干冰撒向天空,实施人工降雨,这是通过干冰______为气体,而吸收热量;天空中的水蒸气______成小冰晶; 小冰晶在下落过程中______成水来实现的.(填物态变化过程)
【单选题】This 80-200mm zoom lens bears canon’s L designation, denoting a top-of-the-line lens built to extremely high ( ).