Questions

A promise. 

The Promise made to somebody by you can be break but you cannot touch it.

Allows for expansion or contraction of the trachea. Hence, so large masses of food can pass through the esophagus during swallowing.

The purpose of hydrogenating unsaturated fats is to make them more solid at room temperature as it is easy store the product.

Secondary succession means in an ecosystem renewal of itself after all or a portion has been destroyed.

After a forest fire, the whole forest had destroyed but after that again renewal of that forest is also an example of secondary succession.

Foot ball game lasts for 60 minutes in total. It is divided into 4 quarters of 15 minutes each and two halves of 30 minutes each.

Joseph Priestley and Carl Wilhelm Scheele both independently discovered oxygen in the year 1774, but Priestly is usually given credit for the discovery.