a. A pen was bought by Hari.
b. A poem has been written by the boy.
c. Tourist were attracted by the national park.
d. Sweets are liked by children.
e. A chair is made being made by Anil.
Step-by-step explanation:
In active voice: doer is suppose to be in the front of the sentence and receiver is suppose to be at the back of the sentence.
In passive voice: does is suppose to be at the back of the sentence and receiver is suppose to be at the front of the sentence.