Do collagen supplements really work? The team behind this review assessed the results of 113 trials involving nearly 8,000 people, and say it brings together the strongest evidence to date on collagen ...

推荐的是一个tab，优点是比较便捷，而且层级明显，缺点是不同的编辑器对tab Size的理解不一样。某些书籍推荐使用4个空格做缩进，优点是不会被代码编辑器缩进所干扰，缺点是要敲比较多的空格 多行注释 ...