Find a mistake in each sentence then correct it

II. Find a mistake in each sentence then correct it. (10 points)
1. Each of the students in the class has to type their own report.
                             A             B            C                 D
2, Many kinds of tigers are at danger now.
      A                B                  C               D

3, Mary likes to go shopping lonely on the weekend.
               A      B B                       C      D  
4, It was such a worrying news that they all kept silent on being informed                                                                                          A      B         B               C   C                   D    D           D
5, Building thousands of years ago, the ancient palace is popular with  modern tourists.
           A                                       B     C       C                         D        D