ecret of nature, they young scientisthas little time for entertainment.

(2014·东北三省三校一联)Traffic conditions in Beijing________for decades.At first people only complained about jams during rush hours，but today every hour is rush hour

_____ are in the army.

This robot is supposed to save a lot of labor, but it remains a problem if it ______.

Every time I went to visit Mount Tai, it __ me with its nature beauty.