【题目】文中共有10处语言错误，每句中最多有两处。每处错误仅涉及一个单词的增加、删除或修改。
增加：在缺词处加一个漏字符号（∧），并在其下面写出该加的词。
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。
When I first came to China, there were many things I do not understand. Now, I have a better understanding of Chinese culture and find it very interested.
Bargaining is a Chinese custom what amazes me. In the USA, prices are set and you cannot ask for a lower price, when in China, you are expected to bargain with the salespersons in some small stores and tourist spots. I once asked my Chinese friends to teach me how to bargain. They were told me that I should ask for 40 percent or 50 percent off the price. Then, they had better tell the salesperson that the same item is cheaper at another store. If the salesperson does not agree to my price, I should pretend leave and he might ask me to come back and sell me the item for a lower price. But this skill doesn’t work effective every time. In my opinion, bargaining are a skill that I have to practise if I continue to live in China.
This is a unforgettable experience for me, which is beneficial to me.
在线课程【答案】
【解析】根据When I first came to China, 可知是发生在过去的事情，所以用一般过去时。
V+ed修饰人，而v+ing修饰物，这里修饰物，所以用v+ing形式。
这里含有一个定语从句，关系词在从句中作主语，指物，所以what改成which / that。
这里表示转折，所以用表示转折关系的连词。
“他们”和“告诉”之间是主动关系，所以用主动语态。
句意：我最好告诉店主。所以they改成I。
Pretend to do是固定用法，意思是假装做某事。
用副词修饰动词。
V+ing作主语，谓语动词用单数。
unforgettable的首字母发音是元音，a改成an。