(1) CH2=CH2 reacts with water to produce A, A is ethanol; ethanol catalytic oxidation to get B, B is acetaldehyde; reacts with aqueous sodium hydroxide to produce C, C is; catalytic oxidation to get D, D is,

The answer is:;

(2) reaction ② by-products of water, reaction ③ by-products of sodium chloride, reaction ④ by-products of water, reaction ⑥ The by-products of reaction ① and ⑤ are water, reaction ① and ⑤ have no by-products, and the atomic utilization rate is 100%, so the answer is: ①, ⑤;

(3) Reaction with aqueous sodium hydroxide produces C, and C is, and the equation is:; Acetaldehyde reacts with to produce E, and E is, and an elimination reaction occurs to get F, and F is, so reaction ⑥ is an elimination reaction,

so the answer is:; elimination reaction;

(4) The isomers of (1), (2), (3), (4), (5) and (6), are water. ) isomerism, there are two substituents on the benzene ring, one of them is carboxyl, then the other is ethyl, the two substituent position relationship can be neighboring, intermediate, and pairs, so *** with 3 kinds,

So the answer is: 3;

(5) a, there is aldehyde group, can react with silver ammonia solution, so a is correct;

b, there is hydroxyl group, can react with sodium, so b is correct;

(5) a, there is aldehyde group, can react with silver ammonia solution, so a correct;

b, there is hydroxyl group, can react with sodium, so b is correct;<

c, a benzene ring can react with with 3 hydrogen, an aldehyde group can react with 1 hydrogen, so 1 mol can react with up to 4 mol of hydrogen, so c is wrong;

d, in the *** with 7 hydrogen atoms, so there are 7 peaks in the NMR*** vibrational hydrogen spectra, so d is wrong;

Therefore the answer is: ab.