题目选项分析

Hydrocarbons, with which fruit flies perfume themselves in species-specific blends, are known to be important in courtship, apparently assisting flies that taste the hydrocarbons on prospective mates in distinguishing their own species from others.

Hydrocarbons, with which fruit flies perfume themselves in species-specific blends, are known to be important in courtship, apparently assisting flies to taste the hydrocarbons on prospective mates to distinguish their own species from those of others.