第7题: [单项选择]This phenomenon still has many of them {{U}}wondering{{/U}} their heads. A. fidgeting B. meditating C. worrying D. scratching 参考答案:D 答案解析:[分析] 词语运用
scratch one's head表:认真地思索一个难题;例:This crisis has politicians scratching their heads and
第8题: [单项选择]酸碱滴定法测定苯唑西林钠含量的依据(原理)为 A. 其钠盐的水解反应 B. 其钠盐水溶液的碱性(因本品为弱酸强碱盐) C. 噻唑环的降解反应 D. 内酰环的水解反应 E. 侧链芳环的降解反应 参考答案:D