(20 14? Carbon is the basic element of many substances. (1) The content of PM2.5 in the atmosphere leads to haze weather, which mainly comes from

(1) Fossil fuels mainly include coal, oil and natural gas. Coal is a complex mixture, which mainly contains carbon, hydrogen, a small amount of nitrogen, sulfur, oxygen and inorganic minerals. Oil is also a mixture, mainly containing carbon and hydrogen; Natural gas is mainly gaseous hydrocarbons composed of carbon and hydrogen, the most important of which is methane; So the answer is: oil? Methane (or CH4); ?

(2) Let the valence of manganese be X, and it is known that the valence of carbon in manganese carbonate is +4 and the valence of oxygen is-2;

x+4？ 2MnCO3

Shows that the algebraic sum of positive and negative valence in the compound is zero.

x+4+(-2)×3=0

Solution: x =+2; So the answer is:+2;

(3) According to the meaning of the question, the reactants are metallic sodium and carbon dioxide, and the products are diamond (C) and sodium carbonate. The reaction condition is 440℃ and high pressure, so the chemical equation of the reaction is: 4Na+3CO2? 440℃ and high pressure? . ? 3C+2na 2 co 3； So the answer is: 4Na+3CO2? 440℃ and high pressure? . ? 3C+2na 2 co 3；

(4) "Carbon sponge": It is composed of carbon elements, has a porous structure and has good elasticity. The oil has strong adsorption capacity (no water absorption), and the sucked oil can still be restored to its original state after being squeezed out.

A, from the meaning of the question, we can know that "carbon sponge" has a porous structure, so it has adsorption; Therefore, A is correct;

B "The sucked oil can still be restored to its original state after extrusion" means that it can be reused; Therefore, B is correct;

C, "it has a strong adsorption capacity for oil (no water absorption)", so it can deal with oil leakage at sea; Therefore, C is correct;

So the answer is: ABC ..