RMD007 wrote:
Hi,
I was confused between C and D but selected C.In your explanation, you have compared events "focused" and "smoked" with respect to their time frames and thus the use of past perfect is proper according to you.
I have two queries.
1. In my thought, we can use past perfect tense for earlier event and simple past tense for later event only if the events are RELATED to each other. Here smoking of people has not resulted in focusing of study. So use of past perfect tense
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