The first compact microwave ovens were sold in 1960. Everybody didn’t use them until the 1980’s. a. comma b. and c. or d. but e. because which one would best suit the sentence structure
The first compact microwave ovens were sold in 1960, but everybody didn’t use them until the 1980’s. But is used to connect the 2 sentence because the two sentences give contradicting ideas Microwave oven was sold during 1960 however people did not use it until the 1980s. According to the rule of world language, if two given sentences gives idea with contradiction, you use but, yet, however, etc. For example: => I bought a power bank online but I did not received it. => I love sweets however too much is yucky.