138.
A. replace is incorrect for the reason in D.
B. to replace is incorrect as it is in the active voice and a lubricant cannot replace something, only someone can replace a lubricant.
C. replacing is incorrect as it is a gerund and the sentence needs V3 = replaced.
D. replaced is correct as it means to be replaced which would also have been correct, but some verbs don’t need ‘to be’ in the passive voice, for example ‘want’:
The boss wanted the work done/completed/corrected before noon.
139.
A. could finish is incorrect because it refers to a future not a past action (a year ago).
B. finished is past tense but not conditional. After I wished, you need to use the past conditional tense.
C. were finished also refers to the future and I wished is in the past.
D. could have finished is correct because it is the conditional past tense.
140.
Only B can be correct because it describes what happened to all the processes. They were not contradicted, or made expedient or diversified. The processes were integrated that is, they were brought under one control (became part of one thing).