The two characteristics that make synthetic polymers beneficial to humans are:
a) Flexible
d) Lightweight
Here's a breakdown of why some of the listed characteristics make synthetic polymers beneficial to humans:
Beneficial characteristics:
Flexible: This allows synthetic polymers to be used in a wide range of applications where flexibility is crucial, such as clothing, hoses, sports equipment, and medical devices.
Lightweight: Many synthetic polymers are significantly lighter than traditional materials like metal or wood, making them ideal for applications where weight matters, like aircraft parts, building materials, and footwear.
Non-beneficial characteristics:
* Hard: While some synthetic polymers can be hard (think hard hats or protective gear), it's not a universally beneficial characteristic. Most often, flexibility or even moderate hardness is preferred for various applications.
* Non-biodegradable: This can be a major drawback of some synthetic polymers due to their environmental impact. While the durability offered can be advantageous in some cases, non-biodegradability contributes to plastic pollution and waste management challenges.
Therefore, the two characteristics that make synthetic polymers beneficial to humans are:
a) Flexible
d) Lightweight
Note:
While hardness can be beneficial in specific applications, it's not a general advantage for most uses of synthetic polymers. Non-biodegradability, despite offering some advantages, poses significant environmental problems and is an area of active research for developing more sustainable alternatives.
I hope this provides a clear explanation and helps you assess the benefits of different synthetic polymer characteristics.