Some fruits and vegetables must be stored at zero to four degrees Celsius.

VOA: special.2009.11.30

They want to get as far away from each other possible, the ideal angle is 120. But what we have here is a four-membered ring, so what angle does 90° that have to be, that bond? 90 degrees.

它们想要尽量远离彼此，最理想的是形成120°键角,但现在是个四元环,所以这键角应该多大？

麻省理工公开课 - 化学原理课程节选

So if we still have an angle of a 109 . 5 degrees, and again, we still have four unpaired electrons available for bonding, we can make one of those bonds with another s p 3 hybridized carbon, so we're going to make up one pair here.

如果键角仍然是109。,同样，我们还有4个未配对的电子可以用来成键，我们可以用其中的一个,和另外一个sp3杂化碳原子成键，这样我们可以组成一对。

麻省理工公开课 - 化学原理课程节选

The researchers say they were able to store the vaccines for four months at forty-five degrees Celsius with no loss of quality.

VOA: special.2010.02.24

Some foods need to be stored at four to eight degrees, and some need to be stored above eight degrees for best results.

VOA: special.2009.11.30

Dorothy Height went on to earn bachelor and master's degrees in four years at New York University.

VOA: special.2010.04.24

The Earth takes twenty-four hours to complete one full turn or revolution of three-hundred-sixty degrees.

VOA: special.2010.07.14

The fires may be as hot as one thousand four hundred degrees Celsius.

VOA: special.2009.09.14

Women also earned fifty and four-tenths percent of the doctorate degrees.

VOA: special.2010.09.16

"Early last week we saw a number of locations in northern NSW [New South Wales and southern Queensland break their August record high temperatures by four or five degrees,".

VOA: standard.2009.09.03