预防Ⅰ型变态反应所致哮喘发作宜选用()
A.克伦特罗
B.肾上腺素
C.沙丁胺醇
D.异丙托溴铵
E.色甘酸钠
参考答案:E
One of the most () challenges that the United States-and indeed, the world-will face in the next few decades is how to alleviate the growing stress that human activities are placing on the environment.
A.consequential
B.subsequent
C.emergent
D.pressing