Using the passive voice with that-clauses: แบบฝึกหัด

Which of the following sentences correctly uses the passive voice with a that-clause to express a general belief?

Read the following active sentence:

"Many historians think that the ancient city was destroyed by a volcanic eruption."

Which of the following is a grammatically correct passive transformation starting with the subject of the that-clause?

Convert the following sentence into the personal passive voice starting with the subject of the that-clause:
"People report that the new curriculum improves students' reading skills."

Rewrite the following sentence by changing the active voice into the passive voice to emphasize the receiver of the action:

The researchers observed that the acetic acid broke up the calcium in the eggshell.

Transform the following active sentence into the impersonal passive voice with a that-clause:
"Scientists believe that chemical reactions accelerate when temperature increases."

Convert the following sentences into the passive voice using a that-clause. Start your sentences with the impersonal "It..." construction.

Example: People say that he is a genius. → It is said that he is a genius.

a) Experts believe that the climate is changing rapidly.
b) Historians think that the castle was built in the 12th century.
c) Journalists report that the two companies have merged.

Analyze the following sentence: "It is often claimed that eating chocolate improves memory."

a) Identify the grammatical structure used (Passive voice with that-clause).
b) Rewrite the sentence starting with the subject of the that-clause: "Eating chocolate..."
c) Explain the difference in emphasis between the two versions.
d) Provide another example of this transformation using the verb 'believe'.