Here are the answers to your questions:
Find the word which has a different sound in the part underlined.
1. C. chemical (The "ch" in "chemical" is pronounced as /k/, while in the others it is pronounced as /tʃ/.)
2. A. grocery (The "ce" in "grocery" is pronounced differently from the others.)
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Choose the word which has a different stress pattern from the others.
3. B. enjoy(The stress pattern in "enjoy" is different from the others, which are all stressed on the first syllable.)
4. D. volunteer (The stress in "volunteer" is on the last syllable, while the others are stressed on the first syllable.)
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Choose the best answers to complete the sentences.
5. B. values
6. C. organic
7. D. was translated
8. A. apologize
9. B. environmental
10. D. Life skills
11. C. are going to travel
12. B. so
13. C. refillable
14. A. ancient
15. D. is wearing / looks
16. C. to learn
17. D. turn off
18. C. trumpet
19. A. will be planted
20. B. but
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Mark the letter A, B, C, or D on your answer sheet to indicate the correct arrangement of the sentences to make a meaningful paragraph/letter in each of the following questions.
21. C. I think children should do housework for a number of reasons.
A. First, doing housework helps children develop some important life skills such as doing the laundry, cleaning the house or taking care of others.
B. They will certainly need those skills in their lives later, when they start their own families.
(So the correct order is CAB.)
If you have any other questions or need further assistance, feel free to ask!