.Although it had been______ struggle for him to finish the experiment, he enjoyed the result with________ satisfaction.
Susan decided not to work on the program at home because she didn’t want her parents to know what she______ .
The astronauts found that ______ the spaceship went further and further into space, it became more and more difficult to control its own movements.
What he said suggested he ______ angry with us so I suggest you ______ an apology to him.
Have you ever been to Mount Huangshan, ___________is famous for its pine forests and "sea of clouds"?
writing the article, Mrs. Curie even forgot her dinner.