短文改错（10分）

下面短文中共有10处错误，每句中最多有两处。错误涉及一个单词的增加、删除或修改。

增加：在缺词处加一个漏词符号（∧），并在此符号下面写出该加的词。

删除：把多余的词用斜线（\）划掉。

修改：在错的词下划一横线，并在该词下面写出修改后的词。

注意：1、每处错误及其修改均仅限一词；

2、只允许修改10处，多者（从第11处起）不计分。

Many students feel it that a popular teacher must be kind and easy-going．He and she should make the class very active for joking with the students．However, the popular teacher is at same time the one who should be strict in students．Last year, my English teacher proved to be the more popular in our school．She was usual patient with her students and never made them disappointed．She always stays in full control of the situations．She always made sure that our homework was finished on time, but she marked strictly on student’s actual performance．

旅行社与游客甲签订的旅游合同生效后，如果双方就旅游行程、价款、服务标准等内容没有约定或者约定不明确的，是不可以通过协议补充的。( )