1 . Tai chi, part of Chinese culture, is a kind of exercise which helps people improve _______________ (they) in health. (所给词的适当形式填空)

2 . As well as looking at exhibits, visitors can play with computer simulations (模拟) and imagine ______ (they) living at a different time in history or walking through a rainforest. (所给词的适当形式填空)