Tobacco contains a chemical substance called nicotine which causes intoxication.
Fill in the blanks.
(a) ………… is produced under the skin in early morning sunlight.
(b) Deficiency of vitamin C causes a disease called ………… .
(c) The substance ………… in tobacco is harmful for both the heart and the brain.
(d) Taking intoxicating substances has adverse effects on the ………… .