АНГЛИЙСКИЙ! CРОЧНО! БУДУ БЛАГОДАРЕН !! НУЖО ВСТАВИТЬ PAST SIMPLE ЛИБО PAST CONTINUOUS
While Trevor Baylis (to listen) to a radio programme about villages in rural Africa, he (to have) a great idea. According to the programme, most villages (not to have) electricity, so communication with the outside world … (to be) a problem. While people in cities (to receive) the latest health information, people in the countryside (not to get) enough information and education. Baylis …(to go) to his workshop and … (to begin) experimenting. He soon (to make) a working radio with no batteries - wind-up radio. While he (to try), without luck, to sell his idea to companies, he (to have) a lucky break. His radio (to appear) on a BBC TV programme, and someone who had money to invest in the project (to do) it. As a result, the Freeplay radio (to become) a huge success.

While Trevor Baylis was listening to a radio programme about villages in rural Africa, he had a great idea. According to the programme, most villages did not have electricity, so communication with the outside world was a problem. While people in cities were receiving the latest health information, people in the countryside were not getting enough information and education. Baylis went to his workshop and began experimenting. He soon made a working radio with no batteries - a wind-up radio. While he was trying, without luck, to sell his idea to companies, he had a lucky break. His radio appeared on a BBC TV programme, and someone who had money to invest in the project did it. As a result, the Freeplay radio became a huge success.

Explanation:
The sentence "While Trevor Baylis (to listen) to a radio programme about villages in rural Africa, he (to have) a great idea" implies that both actions of listening and having the idea happened at the same time in the past. Therefore, we use the past continuous tense "was listening" and the past simple tense "had" in this sentence.

The sentence "According to the programme, most villages (not to have) electricity, so communication with the outside world … (to be) a problem" refers to a general situation in the past, so we use the past simple tense "did not have" and "was" to indicate this.

The sentence "While people in cities (to receive) the latest health information, people in the countryside (not to get) enough information and education" also shows simultaneous actions in the past. Therefore, we use the past continuous tense "were receiving" and "were not getting" in this sentence.

The sentence "Baylis …(to go) to his workshop and … (to begin) experimenting" describes a sequence of actions in the past. First, Baylis went to his workshop, and then he began experimenting. So, we use the past simple tense "went" and "began" in this sentence.

The sentence "He soon (to make) a working radio with no batteries - wind-up radio" indicates a completed action in the past. Baylis successfully made a working radio, so we use the past simple tense "made."

The sentence "While he (to try), without luck, to sell his idea to companies, he (to have) a lucky break" describes simultaneous actions in the past. While Baylis was trying to sell his idea, he had a lucky break. Therefore, we use the past continuous tense "was trying" and the past simple tense "had" in this sentence.

The sentence "His radio (to appear) on a BBC TV programme, and someone who had money to invest in the project (to do) it" describes two completed actions in the past. First, his radio appeared on a BBC TV programme, and then someone invested money in the project. So, we use the past simple tense "appeared" and "invested" in this sentence.

The sentence "As a result, the Freeplay radio (to become) a huge success" states a result of the previous actions. The Freeplay radio became a huge success, indicating a completed action in the past. Therefore, we use the past simple tense "became" in this sentence.