CLASS 10
THE MAKING OF A SCIENTIST
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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work-began
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have worked-have began
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has worked-has began
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have worked-began
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Detailed explanation-1: -The present perfect is formed using the present tense of the verb “to have” and the past participle of the main verb. The past perfect tense says that an action was completed at a time before another action happened in the past.
Detailed explanation-2: -We have already learned that the simple present tense is used to talk about routines. The present perfect tense is used to talk about events that have just completed.
Detailed explanation-3: -Use the simple past when the action started in the past, finished in the past, and is not continuing now. Use the present perfect when the action started in the past and is continuing now. The simple past tells us that an action happened at a certain time in the past, and is not continuing anymore.
Detailed explanation-4: -Answer: The train has arrived just now.