Исправте меня, пожалуйста, если я где-то ошиблась. Нужно выбрать правильную грамматическую форму.

1. He (1)___ for her for two hours before she (2)___.
A. (1) has been fishing,
(2) cameB. (1) was fishing,
(2) cameC. (1) had been fishing,
(2) came
He was fishing for her for two hours before she came.

2. The car ___ once every three months.
A. polishesB. is polishedC. polished
The car is polished once every three months.

3. The light ___ off yet.
A. has not turnedB. has not been turnedC. was not turned
The light has not been turned off yet.

4.We all felt these words ___.
A. be trueB. trueC. to be true
We all felt these words true.

5. This thing is difficult ___.
A. to imagineB. imagineC. imagines
This thing is difficult imagine.

6. She was ashamed ___ her best clothes.
A. had not wornB. did not wearC. not to have worn
She was ashamed did not wear her best clothes.

7. We talked of ___ abroad.
A. he is sent B. his being sentC. he was sent
We talked of his being sent abroad.

8. ___ chemicals, the fireman soon put out the fire in the forest.
A. UsingB. UsesC. To use
To use chemicals, the fireman soon put out the fire in the forest.

16. ___ reading the book, he took it back to the library.
A. Have finishedB. Having finishedC. Finished
Having finished reading the book, he took it back to the library.