In sexual reproduction, offspring are similar to their parents, but unique as well.
a. true
b. false

The given statement is true.

Explanation:

Different strategies are used by living species for generating offspring, however, the majority of them come into the categories of either asexual or sexual reproduction. The offspring in asexual reproduction are genetically similar to a single parent. On the other hand, in sexual reproduction, two parents take part in providing genetic information to generate a unique offspring. Thus, the given statement is correct.  

false because ozone (o3) depletion does not cause global warming, but both of these environmental problems have a common cause: human activities that release pollutants into the atmosphere altering it.

global warming is caused primarily by putting too much carbon dioxide into the atmosphere when coal, oil, and natural gas are burned to generate electricity or to run our cars.

explanation:

in a chemical reaction, the atoms and molecules produced by the reaction are called products. no new atoms are created, and no atoms are destroyed. in a chemical reaction, reactants contact each other, bonds between atoms in the reactants are broken, and atoms rearrange and form new bonds to make the products.