No matter how ______,scientists are eager to know more about it by exploring.
.Don't ____ when other people are talking.
After supper she would sit down by the fire , sometimes for _____an hour , thinking of her young and happy days.
It was several minutes before I was ____ of what was happening.
I ____ you a very happy future.
All their attempts to rescue the child from the burning building were _____. He died soon afterwards.