环境污染物进入人体的主要途径是
A.皮肤、粘膜和结膜
B.血液、唾液和淋巴液
C.呼吸道、消化道和皮肤
D.鼻腔、口腔和眼
E.腮腺、淋巴腺和扁桃腺
参考答案:C
—What does the sigh mean?
—It means "_____". [ ]
A. Plant trees
B. Be careful
C. Save water
D. Take care of the earth
分子式为CH2Cl2的有机物同分异构体共有(不考虑立体异构)( )
A.1种
B.2种
C.3种
D.4种