11.   If it turns out that your teenager is using drugs and has problems, you have something very painful to face.

12.   It became more and more obvious that the boy was using drugs.

13.   It might be much bigger if the drug could be used to prevent, as opposed to treat, prostate cancer.

14.   Many of these people had used drugs in their youth.

15.   More generic drugs are now used, and stocks are much more carefully controlled.

16.   Now, fruit trees are sprayed to cure their diseases, and salmon farmers use drugs by the sack.

17.   One-third of girls and almost two-fifths of boys admitted having used illicit drugs.

18.   Only hormone-deficient children are allowed to use the drug.

19.   Patients with eating disorders may use drugs to induce vomiting.

20.   Powerful drugs are used to arrest the spread of the disease.