Which of the following is a positive statement?

a) A humidity level of 90 percent is too high.
b) It is too hot to run outside when the temperature exceeds 80 degrees.
c) The temperature is 92 degrees today.
d) Summer evenings are nice when it cools off to around 70 degrees.

Engineers find a new metal that is stronger than steel but much lighter. this material is also significantly cheaper than what is currently used for most aircraft, available in large quantities, and easy to manufacture. the engineers are excited because this new material will lower the costs of buying and operating airplanes for companies. what is probably the best step for the engineers to make next?

In general what determines whether atoms will form chemical bonds?

How can a cyclist's acceleration change even if its velocity remains constant?