Growing up _____ be difficult, for you will come across many things that confuse you．

I know that if I start watching a soap opera, I immediately become hopelessly _____.

—This teaching method seems good.—True. It can be __________ in a few selected schools to see how it works in practice.

You had better ______some time every day for sports so that you can keep yourself energetic.

With that information ____, I sought out Douglas Smith, director of the Center for Brain Injury and Repair at the University of Pennsylvania.