下列有关c<sub>2</sub>的说法正确的是()。
A、缓坡
B、陡坡
C、壅水曲线
D、降水曲线
A、缓坡
B、陡坡
C、壅水曲线
D、降水曲线
A、温室效应—CO<sub>2sub> B、臭氧层变薄—SO<sub>2sub> C、酸雨—SO<sub>2sub> D、生物大作用—DDT E、富营养化—O<sub>2sub>太多
A、粗砂μ<sub>fsub>=3.7—3.1中砂μ<sub>fsub>=3.0—2.3细砂μ<sub>fsub>=2.2—1.6 B、粗砂μ<sub>fsub>=3.7—3.3中砂μ<sub>fsub>=3.2—2.5细砂μ<sub>fsub>=2.4—1.6 C、粗砂μ<sub>fsub>=3.7—3.2中砂μ<sub>fsub>=3.1—2.4细砂μ<sub>fsub>=2.3—1.6 D、粗砂μ<sub>fsub>=3.7—3.0中砂μ<sub>fsub>=2.9—2.2细砂μ<sub>fsub>=2.1—1.6
A、HOCH<sub>2sub>COOH B、HOCH<sub>2sub>CH<sub>2sub>COOH C、HOCH<sub>2sub>CH<sub>2sub>CH<sub>2sub>COOH D、HOCH<sub>2sub>CH<sub>2sub>CH<sub>2sub>CH<sub>2sub>COOH
A、C<sub>6sub>H<sub>5sub>CH<sub>2sub>CO<sub>2sub>H B、CH<sub>3sub>CH<sub>2sub>CO<sub>2sub>H C、BrCH<sub>2sub>CH<sub>2sub>CO<sub>2sub>H D、C<sub>1sub>CH<sub>2sub>CH<sub>2sub>CO<sub>2sub>H
A、CH<sub>2sub>=CHC(CH<sub>3sub>)=CH<sub>2sub>; B、CH<sub>2sub>=C-(NO<sub>2sub>)<sub>2sub>; C、CF<sub>2sub>=CF<sub>2sub>; D、CH<sub>2sub>=CHCH<sub>3sub>
A、O<sub>2sub>,B<sub>2sub> B、C<sub>2sub>,O<sub>2sub> C、Be<sub>2sub>,F<sub>2sub> D、H<sub>2sub>,He<sub>2sub>+
A、CH<sub>4sub>+2O<sub>2sub>=2H<sub>2sub>O+CO<sub>2sub> B、2CH<sub>4sub>+3O<sub>2sub>=4H<sub>2sub>O+2CO C、CH<sub>4sub>+O<sub>2sub>=H<sub>2sub>O+CO<sub>2sub> D、CH<sub>4sub>+O<sub>2sub>=H<sub>2sub>O+CO
A、Fe<sub>2sub>O<sub>3sub>+3H<sub>2sub>SO<sub>4sub>==Fe<sub>2sub>(SO<sub>4sub>)<sub>3sub>+3H<sub>2sub>O B、Cu(OH)<sub>2sub>+2HCl==CuCl<sub>2sub>+2H<sub>2sub>O C、CaCO<sub>3sub>+2HCl==CaCl<sub>2sub>+H<sub>2sub>O+CO<sub>2sub>↑ D、BaCl<sub>2sub>+H<sub>2sub>SO<sub>4sub>==BaSO<sub>4sub>↓+2HCl
A、H<sub>2sub>、O<sub>2sub>、SO<sub>2sub> B、NH<sub>3sub>、O<sub>2sub>、HCI C、H<sub>2sub>、F<sub>2sub>、CO<sub>2sub> D、O<sub>2sub>、CO、NO