单项选择题 DVDs are most effective ______ the discs are sturdy and the crisp images do not degrade with repeated showings.

单项选择题 A peninsula surrounded by more than 200 islands, Hong Kong is one of the most densely ______ urban regions on the planet.

单项选择题 As a result of poor management, Sableline, a company once famous the world over for its quality toys, is ______ to close down in two years.