下面是某高中教师在新授环节之后设计的课堂练习

问答题下面是某高中教师在新授环节之后设计的课堂练习。
Join the pairs of sentences using attributive clauses（restrictive or non-restrictive）.
Here are the farmers. They discovered the underground city last month.
Hangzhou is a famous city in China. Many people come to buy tea in that city.
She got so angry. I don＇t know the reason.
The old man saw some Germans taking apart the Amber room and removing it. You are talking to an old man.
The woman remembered the day. She saw Nazis burying something near her home.
St Petersburg is a very beautiful city. It was once called leningrad.
I remember the soldier he told me not to tell an yone what i had seen.
The soldiers moved the boxes to a mine. They wanted to hide them.
Xi an is one of the few cities with city walls. Its walls remain as good as before.
Shanxi Province is a place with many cultural relics. They are well looked after.
根据上面所给的信息，从下列三个方面作答
（1）分析此练习题的目的。
（2）分析此练习题的弊端。
（3）教师在安排学生课上练习题时的注意事项有哪些？