Ecologists are trying to preserve our environment for future generations by protecting the ozone layer, purifying the air, and have planted the trees that have been cut down.

Please tell us the reason when he left without saying goodbye.

When many of my friends take a shower in the morning, I usually take one before bed.

For the first time in the history of the country, the person which was recommended by the president to replace a retiring justice on the Supreme Court is a woman.

The mother asked her son if he would have the floor clean the day before.

Câu 226: Teddy Roosevelt demonstrated his competitive spirit and tireless energy in 1905 whenever he led the Rough Riders up San Juan Hill.

Working provide people with personal satisfaction as well as money.

Unless there had been a heavy storm, the climbers will not have died.