n DNA, thymine always pairs with and cytosine always pairs with by forming ( across complementary strands.

According to your text, should be in the native language of the parents or guardians whenever possible. a. an email b. consent forms c. oral approval d. storybooks loaned out

Long term exposure to waves can cause sunburns and skin cancer.

The greenhouse effect a. something that has occurred for millions of years b. an unnatural phenomenon caused by humans that maintains earths temperature range. c. the results of the differences in the angle of the suns rays d. an unnatural phenomenon that causes heat energy to be radiated back into the atmosphere