Ответ:

1b:

2. are sitting

3. am writing

4. is hiking

5. are playing

6. are learning

7. are studying

8. are swimming

Объяснение:

Present Continuos (Простое настоящее время) образуется с помощью To Be (am только с 'I', is с it, he, she; и are, если множественное число) + глагол с окончанием -ing

2:

2. Is your mum working now? Yes, she is

3. Are your friends studying now? No, they are not

4. Are your grandparents having a dinner now? Yes, they are

5. Are your teacher telling you a story now? Yes, she is

6. What are you doing now? I'm reading

7. What is your pet doing now? He's playing