Dating sediments using ragweed and nuclear fallout
利用豚草及核放射物对沉积物进行年代推定
Whether the trigger is pollen or ragweed , suffering during allergy season is no fun .
不管让你过敏的是花粉或者豚草，在过敏季节要经受的煎熬滋味可一点也不好。
For 75 percent of those 35 million , ragweed is the primary allergen , he added .
对于这35000000人的75%来说，豚草是首要过敏原，他补充道。
People with ragweed allergies are more likely to have a reaction to echinacea , and there have been cases of anaphylactic shock .
对豚草过敏的人更可能由紫锥菊引发生理反应，甚至有引起过敏性休克的案例。
The findings correlate with analysis last year by the national wildlife federation that found ragweed growth rates and pollen counts increased with global warming .
