1. The scientist has been determined to continue the test in spite of late hours.
(Has, Who, What)
Has the scientist been determined to continue the test in spite of late hours?
Who has been determined to continue the test in spite of late hours?
What has the scientist been determined to continue in spite of late hours?

Note: по самой фразе - The scientist has been determined - это сущая чепуха.
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2. The company will send them the goods after they have received the documents.
(Who, What, When)
Who will send them the goods after they have received the documents?
What will the company send them after they have received the documents?
When will the company send them the goods?
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3. By the end of the year, the student had learned to speak French.
(Who, What language. When)
Who had learned to speak French by the end of the year?
What language had the student learned to speak by the end of the year?
When had the student learned to speak French?
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4. The builders have constructed hundreds of new buildings in Moscow.
(Who, What, Where)
Who have constructed hundreds of new buildings in Moscow?
What have the builders constructed in Moscow?
Where have the builders constructed hundreds of new buildings?
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5. The research had been finished before the accident took place.
(Had, What. When)
Had the research been finished before the accident took place?
What had been finished before the accident took place?
When had the research been finished?
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6. The secretary has sent an important letter by email.
(Who, What, How)
Who has sent an important letter by email?
What has the secretary sent by email?
How has the secretary sent an important letter?
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7. The students had finished the course of English by the end of the last year.
(Who, What, When)
Who had finished the course of English by the end of the last year?
What had the students finished by the end of the last year?
When had the students finished the course of English?
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8. The researcher has discovered a new substance.
(Has, Who, What)
Has the researcher discovered a new substance?
Who has discovered a new substance?
What has the researcher discovered?