题目

下图曲线a和b是盐酸与氢氧化钠的相互滴定的滴定曲线，下列叙述正确的是( ) A．盐酸的物质的量浓度为1 mol/L B．P点时反应恰好完全，溶液呈中性 C．曲线a是盐酸滴定氢氧化钠的滴定曲线 D．酚酞不能用作本实验的指示剂 答案：B阅读下面短文，按照句子结构的语法性和上下文连贯的要求，在空格处填入一个适当的词或使用括号中词语的正确形式填空（每空不多于2个单词）。Wang Ling is1.middle school student. English is2.（she） favourite subject. She likes English books3.there are many nice pictures in them. She often tells her parents4.her English study. She likes 5.to the teacher. Her teacher only6.（speak） English in class. Some-times the students can’t understand and then the teacher says it again and again. Wang Ling can speak English 7.（good）. She also likes science because she thinks it’s 8.（interest） and she really likes her science 9.（teach）, Mr Wang. He is very strict（严格的）,10. he is fun. His classes are exciting. 1.a 2.her 3.because 4.about 5.listening 6.speaks 7.well 8.interesting 9.teacher 10.but 【解析】文章介绍了王玲在学校的情况。 1.句意：王玲是一个中学生。根据句意用“一个”，a用于辅音开头的单词前；故填a 2.句意：英语是她最喜欢的科目。on...