$\text{1.}$ is grown

$\text{→}$ Thì HTD: S + is/ are/ am + PP + (by)

$\text{2.}$ are located

$\text{→}$ Thì HTD

$\text{3.}$ are produced

$\text{→}$ each year ⇒ HTD

$\text{4.}$ was planted

$\text{→}$ in + năm ⇒ QKD: S + was/ were + PP + (by)

$\text{5.}$ hadn't been used

$\text{→}$ QKHT + before + QKD

$\text{→}$ Thì QKHT: S + had been + PP + (by)

$\text{6.}$ are helped

$\text{→}$ Thì HTD

$\text{7.}$ is bought

$\text{→}$ Thì HTD

$\text{8.}$ was given

$\text{→}$ in + năm ⇒ QKD

1. is grown ( HTĐ: am/is/are + Vp.p )

2. are located ( như câu 1) 

3. are produced (như câu 1)

4. was planted (QKĐ: was/were + Vp.p )

5. hadn't been used (QKHT: had been + Vp.p )

6. are helped (như câu 1)

7. is bought (như câu 1)

8. was given (như câu 4))

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