[练习题]Directions: Fill in the blank in each of the following statements with one word, the first letter of which is already given as a clue. Note that you are to fill in ONE word only, and you are not allowed to change the letter given.When a sentence is uttered or written down, the words of the sentence are produced one after another in a sequence. This sequential order of words in a sentence shows that the structure of a sentence is l.