Which of the following is considered a second-line defense?
A. circuatory
B. digestive
C. nervous
D. respitory

In the sentence "a mining company will consider the distribution of coal when deciding how to mine the coal," what does the word distribution mean?

Slow down transpiration by the stomata question 9 options: a guard cells; closing b chloroplasts; closing c guard cells; opening d chloroplasts; opening

Which characteristics must an object possess in order to be considered alive?