下列说法正确的是 [ ]

A. 化学键既存在于分子中相邻原子间，也存在相邻分子的原子间

B. 放热反应在任何条件都能自发进行

C. 金属的化学腐蚀和电化学腐蚀的本质相同，但电化学腐蚀伴有电流产生

D. 电解质溶液导电是化学变化，但不一定发生氧化还原反应

What does the speaker feel about summer pictures a. Summer films might cause mental damage to the audience. b. Summer films need to give due respect to the audience’s intelligence. c. Summer films should cater to both children and grownups. d. Summer films should not target at the mass-market.