Most of us spend less time in the sun during the winter, and that means we can end up vitamin d-deficient, leaving us vulnerable to any number of infections.

我们大多数人在冬天会花费很少的时间晒太阳，这方法能使我们摆脱维生素d缺乏症，使我们易受一些感染的攻击。

youdao

Expect it to hit some time before the end of 2011. (All Things d).

预计它将于2011年末的某个时候正式面世。

youdao

The Romans had to keep on cooking up new letters every time their numbers got bigger - C for 100, D for 500, M for 1, 000 - because they didn't have zeros to add on to the end.

当数字增大时，罗马人只能疲于接招，不断地创造出新的字母用来标记数字 —— C代表100，D代表500，M代表1000 —— 因为在他们的数字系统中不能将‘0’添加在数字后面。 想感觉100万有多大？

youdao

Vinas was not able to return to Cuba a third time and was forced to end a relationship he'd begun with a young woman there, he would later tell investigators.

CNN: The radicalization of an all-American kid

When the hotel opened in April 2011, his workouts were sporadic and at the end of the first year as general manager he'd given up finding time to work out.

WSJ: Run to Work, Run a Hotel

Secondly, when I spread myself too thin, the end result is never the quality it would have been if I'd devoted my full time and energy.

CNN: The key to fitness? Schedule it in