【每日逻辑练习第二季】【3-3】

泾渭不凡

premise or background information？（I'm inclined to agree that this sentence is background information）：Cigarette companies claim that manufacturing bothlow- and high-nicotine cigarettes allows smokers to choose how much nicotine they want.
conclusion：A recent study has shown that the levels of nicotine found in the blood of smokers who smoke one pack of cigarettes per day are identical at the end of aday’s worth of smoking.
prephrase: Some factors affect the body's ability to absorb the nictine~

~A~