<span>The discovery of thornless plants was made around the turn of the 20th century. To name one such thornless plant, particularly, the Blackberry plant, the deviation from the thorned blackberry canes were discovered in the United States. Since then, several different thornless blackberry varieties have been cultivated for fruit gardens.</span>
<span>Calcium<span> is the element responsible for most of the material found in teeth.
Calcium plays a vital role in the formation and maintenance of healthy teeth and gums. Calcium makes the jawbones healthy and strong in order to hold the teeth in place.
Dairy foods such as cheese and yogurt, beans, cabbage and brown rice are good sources of calcium.</span></span>
How does the whole question go?