Дополните предложения, выбрав необходимые для этого сочетания слов.1. Why ... to

Дополните предложения, выбрав нужные для этого сочетания слов.
1. Why ... to get this book?
1) it was difficult 2) was difficult 3) was it difficult 4) difficult
2. How many exams ... this year?
1) have you taken 2) you took I 3) you have taken 4) did you take
3. What... to do now?
1) it is necessary 2) is it necessary 3) necessary 4) is necessary