In the following passage some words have been deleted. Fill in the blanks with the help of the alternatives given. Select the most appropriate option for each number.
Passage:

Ourstomach contains hydrochloric acid. It (1)............ us to digest food, but too muchacid (2)........... the stomach causesindigestion.(3)............. indigestion is painful. To (4).......... indigestion, we take (5)........... antacid such as milk of magnesia.