1. It is common to look up, down, and all around when speaking to others, and not have eye contact at all times.
    而你自己对别人说话时，向上、向下、以及向四周看看，这都很平常，你不必一直保持与对方目光的接触。

2. In sub-Saharan Africa and Latin America, particularly the Caribbean, most cases occur among heterosexuals, and spreading from mother-to-child is common.
    在靠近撒哈拉沙漠的非洲地区、拉丁美洲，尤其是在加勒比海地区，大多数病例都发生在异性恋者之间，而且往往是母子之间传播。

3. Iron deficiency is very common among women in general, affecting one in four female teenagers and one in five women aged 18 to 45, respectively.
    缺铁在多数女性中是很常见的，十多岁的少女四人中有一人缺铁，18至45岁的女性五人中有一人缺铁。

4. In some cities, it is common for people to approach you and offer you a ride.
    在某些城市里，有人走近你，并主动提出载你一程，这是很常见的。

5. In places like South America, where it is common to be surrounded by them,
    像在南美这样的地方，通常你会被一圈人围住，

6. From those humble beginnings, we have seen the development of the user-friendly home computers and multimedia machines which are in common use today.
    从那些简陋的初级阶段，我们看到了现在都已普及的、使用简便的家用电脑和多媒体的微机的发展。

7. For instance, it is customary for Germans, particularly male passengers, to sit in the front seat with their taxi drivers, a common practice in Australia as well.
    比如，德国人，特别是男性乘客，习惯和司机并排坐在汽车前座。这在澳大利亚也很常见。