Question

C. Correct the mistakes:
a. Did they putted their books on the shelf?
b. She fixxed the PC very easily.
c. Did you stopped playing the piano?
d. He haved lunch at 2 o'clock.

Answer 1

Hello!

a. Did they put their books on the shelf?

b. She fixed the PC very easily.

c. Did you stop playing the piano?

d. He had lunch at 2 o'clock.

Nota bene! did + short infinitive form of the verb in interrogative & negative sentences

ex: Did you eat...? √

      I did not eat... √