Sustainable technologies are innovations that aim to improve existing products. Phones are a good example. Each year they improve gradually. They might have a bigger screen or better camera than the year before. Perhaps they store more data. The primary uses and purposes of phones, however, do not change. In fact, most phones have the same basic parts
Which of the following best represents the central idea of the passage?*
"They might have a bigger screen or better camera than the year before."
"Sustainable technologies are innovations that aim to improve existing products.
"The primary uses and purposes of phones, however, do not change"
"In fact, most phones have the same basic parts