Which of the following statements is true?
a. spf 10 is the minimum for safe protection from the sun.
b. we need vitamin d from the sun so there is no unsafe exposure level.
c. there is only one kind of harmful uv ray from the sun.
d. from 10am to 4pm are the most dangerous hours for exposure to the sun.

answer is a

Vertebrates have this type of circulatory system: wut i it owo

What is one technique to a person get proper sleep? eat a heavy meal before bed. exercise intensely before bed. practice relaxation breathing before bed. use electronics before bed.

The idea that some faces are inherently more attractive than others is supported by research demonstrating that people we like seem more attractive to us. people prefer averaged composite faces to individual faces. people from different cultures enhance their appearance in different ways. standards of beauty change over time.