in common:共同的
What do they have in common?
他们有什么共同点呢？
I darted left and saw that, according to facebook, we had over 20 friends in common.
我迅速瞄回左边，发现根据facebook的统计，我们拥有20多个共同的朋友。

miss out: (被)遗忘；(被)略去
Many modern humans miss out on this, as we spend our days in constructed environments.
但许多现代人却忽略了这一点，因为他们生活在建造的环境里。
And for those of us who spend entirely too much time in social networks, having these gadgets on hand means we won't miss out on the important information that matters most.
而对于那些在社交网络上耗费太多光阴的人来说，手头有这些小工具即意味着这些人不会再错失那些极其重要的信息了。

at the risk of: 冒…风险
It may never do so, even at the risk of being bombed.
他可能即便冒着被轰炸的危险也不这样做。