A. My father was talking to his friend on mobile phone when I fell from the bicycle.
B. My father was talking to his friend on mobile phone when I fall from the bicycle.
C. My father is talking to his friend on mobile phone when I fall from the bicycle
D. My father was talking to his friend on mobile phone when I am falling from the bicycle.
Explanation
The correct sentence is:
c. My father was talking to his friend on mobile phone when I fell from the bicycle.
This sentence correctly uses the past continuous tense ("was talking") for the ongoing action and the simple past tense ("fell") for the completed action.
A. They were playing football when it started to rain.
B. She will finish her homework before she went to bed.
C. He is going to the market yesterday.
D. I had been waiting for the bus, and it arrives.
Explanation
The sentence with the correct tense and sentence structure is: They were playing football when it started to rain.
This sentence correctly uses the past continuous tense ("were playing") to describe an ongoing action that was interrupted by another action ("started to rain").