He found _____ not easy to learn a foreign language well.
He told his friends that he ___ what he was reading at the same time the day before.
They ___ every means, but the engine __ work.
The workers ___ busily when the boss came to look for something she ___ in the office.
Her brother___ while he ___ his big horse and had his leg broken.
“There is something wrong with my bike.” “It doesn't matter. I ___ lend you mine.”