求翻译：醋酸酐在碱的作用下失去氢原子，生成醋酸酐负离子，该负离子和苯发生亲核加成反应得到羧基酸酐中间体，该中间体受热脱水和水解得到不饱和羧酸是什么意思？

Under the action of acetic anhydride in the loss of alkali hydrogen atoms to produce acetic anhydride anion, the anion and benzene nucleophilic addition reaction of carboxylic anhydride intermediates, the intermediate heat dehydration and hydrolysis of unsaturated carboxylic acid

acetic anhydride in alkali, hydrogen atom lost under role of acetic anhydride generated negative ions occur, the negative ions and benzene pro-nuclear reaction by carboxyl acid anhydride intermediate heat, dehydration and hydrolysis by the intermediate unsaturated carboxylic acid

The acetic anhydride loses the hydrogen atom under the alkali function, the production acetic anhydride anoin, this anoin and the benzene has the nucleophilic addition reaction to obtain the carboxyl group acid anhydride intermediate, this intermediate being heated dehydration and the hydrolisis obt

Acetic anhydride, lost in alkali hydrogen atoms, acetic anhydride, negative ions, the occurrence of negative ions and benzene are carboxylic anhydrides Nucleophilic addition reaction intermediates, dehydration of the intermediate heat and hydrolysis are unsaturated carboxylic acid