【题目】—— A lot of animals are dying out.
—— Yes, especially those that are most s to the changes of the environment.

【答案】sensitive
【解析】考查形容词。句意：--很多动物都在灭绝。--是的，尤其是那些对环境变化很敏感的动物。be sensitive to固定短语“对…敏感”，故“sensitive”即可。