답변을 얻은 뒤 반드시 감사의 덧글을 남기고, 좋은 답변은 채택해 주시는 센스...
질문할 때 예의를 지키시기 바랍니다.(빨리... 고수분만..... 이런 식의 요구는 자제 바랍니다.)
질문 내용 :

기말고사에 모의고사 변형 문제가 나오는데요.. 수동태를 능동으로 고치는 문장이 많습니다.
도대체 어디서부터 어떻게 고쳐야 하는지 너무 복잡합니다.
염치 없지만 설명 부탁드립니다.. ㅠ.ㅠ

1. When I heardfrom my agent that I was asked to sing two songs for your charity, I was really pleased.2. The paper should remain in the bottom when the glass is turned upside down.3. If the glass were turned on its side under water, the air would be released and then water would fill the glass.4. Since all materials that we use are taken from the earth, they have to be returned in order to be used again.5. Nothing is created or destroyed, but everything is changed in form.

6. An apple is obtained from the earth

7. a cycle is set up

부탁드리겠습니다...!