1·For instance, many babies are perfectly proficient crawlers, but they decide to try walking because there's more to see and do when they stand upright.
例如，许多婴儿都能非常熟练地爬行，但他们却决定尝试行走，因为当他们站直时，有更多的东西能看和做。
2·An empty bag cannot stand upright.
空袋不能直立。
3·An empty Bag cannot stand upright.
空口袋站不直。
4·An empty sack cannot stand upright.
空粉袋，站不直。
5·Empty sacks will never stand upright.
空带子站不稳。
6·Sit or stand upright.
站直或坐直。
7·It's hard for an empty bag to stand upright.
口袋空空的人腰杆子是挺不直的。
8·It is hard for an empty sack to stand upright.
对于一个空口袋来说，直立起来是困难的。
9·Some of these flowers stand upright branches, Moon;
这些花有的挺立枝头，含苞待放；
10·December is a friend, pure and proudly stand upright.
朋友是十二月的梅，纯洁又傲然挺立。