Why is third-hand smoke especially harmful to young children? A.They are closer to where toxic chemicals remain. B.Particles are more likely to cling to their hands. C.Their immune system is not fully developeD. D.They haven't formed a good health habit yet.
A.They B. B.Particles C. C.Their D. D.They E.
【参考答案】
A 解析：根据题干中的harmful to young children将本题出处定位到首段末句。该句提到，残留......