题目

Sneaker is a kind of shoe worn by many people all over the world. Some say that the word “sneaker” is another word for tennis shoe, ___21___no one really knows where the word came from. ___22___ say it came from the old English verb “sneak”, which ___23___ to move silently and quickly. The only thing we are ___24___ is that when you put on a pair of sneakers, you ___25___ light-hearted, light-footed and ready to play. Sneakers of some kind are used by ___26___ who play tennis, basketball, and other sports. New design has been made ___27___ for people who run slowly. But p设NA为阿伏伽德罗常数的数值，下列说法正确的是A.5.6g Fe与足量稀盐酸反应转移的电子数为0.3NAB.常温常压下，23g NO2含有NA个氧原子C.标准状况下，22.4L水含有个NAH2O分子D.1mol/L NaCl溶液含有NA个Na+