- It has a half-life of about 41/2 billion years .
- They are of about the same strength .
- The mine had yielded a total of about 3714 tons of coal .
- Seawater invades for a distance of about 50 miles upstream .
- He was a pert little blonde of about six years .
- It's difficult to find of about in a sentence. 用of about造句挺難的
- A man of about twenty-eight spent a summer in our village .
- After the age of about thirty they abandon individual ambition .
- Geodetic theodolites generally have circles of about 140mm diameter .
- New channel are being dredged each year at a cost of about $74,000,000.
- He was a man of about thirty, with a muscular throat and a large, mobile mouth .
- The man went from rags to riches in a short period of about five years .
- For ranges in excess of about 800m some target magnification is required .
- The journey from our town to the metropolis was a journey of about five hours .
- The sister, catherine, was a slender worldly girl of about thirty .
- Next morning at six i set out with a squad of about forty youths .