The harpsichord, developed during the Middle Ages, was one of the forerunners of the piano

During the lecture, the speaker occasionally ___ ？

What made the American film industry develop during the First World War？A．The drastic drop

In certain area, during certain period, the development of communication could ______ the

If something happens to the brains development during pregnancy, it is more likely ______

Most of people develop bad reading habits during their childhood, and never get_____them.A

PC industry has developed rapidly all over the world during the past twenty years.