MA questions. Any one who can explain the grammatical point ? Q1: For centuries, cats have guarded this famous museum, ridding it of mice, rats, and other rodents that could damage the art, not to mention.....off visitors. 1)that of scaring 2)scaring 3)scare 4)having scared Answer key: Choice 3. I don't know why '2' cannot be possible. I know the parallel structure and we have to have the same grammatical structure before and after 'coordinating conjunction' so why not because of 'RIDDING' I can select 'SCARING' when in this case it is parallel? Q2:Most historians trace the beginning of the Internet to Sputnik, the first satelite...... 1)to successfully orbit the earth 2)orbited the earth successfully Answer key: choice '1'. WHY not '2'? I would complete the blank as : 'which was the first satelite orbitted the earth successfully' then I reduce the adjective clause and that will become choice '2' so what's wrong with it? Thanks in advance <3