Question 1:
Correct Answer: B. has existed
The Earth has existed for a very long time, and it's still existing. The present perfect tense ("has existed") is used to express a state that began in the past and continues to the present.
Question 2:
Correct Answer: C. have been
Humans have been on the planet for a period of time that started in the past and continues until now. The present perfect tense is used to express this.
Question 3:
Correct Answer: B. lived
Dinosaurs existed for a specific period in the past and then became extinct. The simple past tense ("lived") is used to describe a completed action in the past.
Question 4:
Correct Answer: A. thought
This sentence describes a belief held in the past. The simple past tense ("thought") is used to express a completed action in the past.
Question 5:
Correct Answer: B. have lived
The Aborigines have been living in Australia for a very long time, and they continue to live there. The present perfect tense is used to express a state that began in the past and continues to the present.
Question 6:
Correct Answer: D. was
The USA was a British colony for a period of time in the past. The simple past tense ("was") is used to describe a state or condition that existed in the past.
Question 7:
Correct Answer: A. has been
The USA gained independence and has been an independent country since then. The present perfect tense is used to express a state that began in the past and continues to the present.
Question 8:
Correct Answer: D. had worked
The action of working abroad happened before he became a banker. The past perfect tense ("had worked") is used to express an action that was completed before another past action.
Question 9:
Correct Answer: B. have lived
The couple has been living in the same place for 25 years, and they are still living there. The present perfect tense is used to express a state that began in the past and continues to the present.
Question 10:
Correct Answer: C. has written
The action of writing books is not a single event in the past; it has happened multiple times. The present perfect tense ("has written") is used to express an action that has been completed multiple times up to the present.