Before the computer could be repaired, a special part had _ _ _ _ _ _ from Germany. Choose the most appropriate word to fill the blank.
A. to import
B. to be imported
C. to have been imported
D. imported

Hint: Any word that can be used to describe an action, state, or occurrence can be called a verb. It forms the main part of the predicate of a sentence. In other words, verbs are words that describe ‘work’ like hear, talk, drink etc. Now that we know what verbs are, let us move on to their different forms. In different situations, people have to adjust with their surroundings.
 Similarly, a verb also must ‘adjust’ itself in different sentences. For example, the only difference between the sentences, ‘I love you’ and ‘I loved you’ is that the speaker (‘I’) loves ‘you’ (to whom it is being spoken) in the former sentence whereas in the latter, the speaker used to love ‘you’ (listener).

Complete answer:
1. Before we move on to find the correct answer, let us first talk about the meaning of the sentence given to us in the question. If we look at the sentence, ‘Before the computer could be repaired, a special part had _ _ _ _ _ _ from Germany’, we can see that the computer could not be repaired due to the lack of the special part which was to be imported from Germany. Therefore, the blank in the sentence should be filled with the option which matches this situation.
2. If we look at the second option, ‘to be imported’, we can see that it meaningfully completes the sentence when filled in the blank. Also, it makes the sentence grammatically correct. Hence, it is the correct answer.
3. The other options like option A, ‘to import’, option C, ‘to have been imported’ and option D, ‘imported’ are wrong because they are not grammatically correct in complying with the usages in this sentence.
4. Therefore, option B is the correct answer to this question. The verb in ‘to be’ form with its principal verb which signifies that the special part ‘had to be imported’ from Germany.

Hence the correct answer is option ‘B’’

Note: We use verbs to describe any action, state or occurrence taking place or being done by the subject. Some verbs are ‘walk’, ‘talk’, ‘laugh’, ‘see’, ‘cry’, ‘dance’, ‘play’ and so on. Verbs have different forms that are used in sentences depending on the tense.