Английский язык, Вопросы

1) Is the book on the table? (Yes/No question, tag questions: "The book is on the table, isn't it?" or "The book isn't on the table, is it?")
2) Are the students in class? (Yes/No question, tag questions: "The students are in class, aren't they?" or "The students aren't in class, are they?")
3) Is she writing an exercise? (Yes/No question, tag questions: "She is writing an exercise, isn't she?" or "She isn't writing an exercise, is she?")
4) Did I cook dinner for my parents yesterday? (Yes/No question, tag questions: "I cooked dinner for my parents yesterday, didn't I?" or "I didn't cook dinner for my parents yesterday, did I?")
5) Are thousands of people visiting the store? (Yes/No question, tag questions: "Thousands of people are visiting the store, aren't they?" or "Thousands of people aren't visiting the store, are they?")
6) Do her dogs eat? (Yes/No question, tag questions: "Her dogs eat, don't they?" or "Her dogs don't eat, do they?")
7) Are there some pillows on the sofa? (Yes/No question, tag questions: "There are some pillows on the sofa, aren't there?" or "There aren't any pillows on the sofa, are there?")
8) Has my friend been to Germany twice? (Yes/No question, tag questions: "Your friend has been to Germany twice, hasn't he/she?" or "Your friend hasn't been to Germany twice, has he/she?")
9) Does the book help to understand people? (Yes/No question, tag questions: "The book helps to understand people, doesn't it?" or "The book doesn't help to understand people, does it?")
10) Were the neighbors on vacation last month? (Yes/No question, tag questions: "The neighbors were on vacation last month, weren't they?" or "The neighbors weren't on vacation last month, were they?")