11.   If discontinued the positive effects disappear within a few months.

12.   In many cases, however, patients see symptoms disappear in within weeks and stop taking the medication.

13.   In fact, nearly all of the crops of both kinds disappeared within the first few years of the experiment.

14.   It exposed a past where black melted into white, where roots tangled and disappeared within a soil of secrecy.

15.   Many had respiratory infections, skin conditions, and parasites, nearly all of which disappear within weeks in response to treatment.

16.   Normal fears usually disappear within six months.

17.   Ocean Energy bought little desk flags for all employees, which were so popular that they disappeared within an hour.

18.   Produced in a cyclotron, they are called short-lived because their radiation disappears within minutes.

19.   She said they disappeared within a matter of hours.

20.   Small software stocks can get buried by larger computer market trends and competitive advantages can disappear within months.