After two half-lives, there is no longer any of the original radioactive material remaining. a) true
b) false

Imagine you work as a consultant, and your daily job involves listening to the constructive criticism of others. as part of your job, you must listen to opposing viewpoints to make important decisions. in this activity, you are a consulting dam engineer. you must make a decision about four different dams; should they be repaired, taken down, or left alone? you will listen to contrasting opinions about what should be done with the dams before you make the final decision. as the consulting dam engineer, what do you decide to do with this dam? explain your reasoning. by making your decision, did you support the opinions of the mayor and/or the dam safety official? why or why not? (site 1)

According to a recent survey, the local government wants to classify people according to their income earning capacity. they want to do so in order to provide special facilities for the poor. who among the four individuals will be classified as poor? a. joseph earns $2.25 per day b. maria earns $1.50 per day c. rosita earns $2.00 per day d. tim earns $ 1.00 per day

Fossils of glossopteris, an extinct fern, were discovered on which continents to support the theory of continental drift? check all that apply.