In the following passage, some of the words have been left out. Read the passage carefully and select the correct answer for the given blank out of the four alternatives. We get sleepy and wake up, become hungry and thirsty at certain hours, ____________ force of habit. We form the habit of liking a certain chair, or nook, or corner, or path, or desk, and __________ seek this to the exclusion of all others. We ______________ use a particular pitch of voice and type of enunciation in speaking, and this becomes one of our characteristic marks; or we _________ the habit of using barbarisms or solecisms of language in __________, and these cling to us and become an inseparable part of us later in life. at certain hours, ____________ force of habit.

Correct Answer: through