How should she compare the hardness of the mineral samples?
A. Scratch each sample with a steel file, then order the samples according to the size of the scratches. B. Use each sample to scratch the other samples, then compare the marks left to determine the order. C. Use an encyclopedia to look up the average hardness of minerals with the same colors as the samples. 11. Chemicals made to kill insects and certain plants are sprayed onto crop fields. A rainstorm washes much of the chemical into nearby streams and ponds. Tell one likely effect these chemicals will have on the number of fishes, frogs, or birds that live in and around the streams and ponds. Give two reasons why the chemicals could have this effect. (Six lines given to write mini-essay.) 12. Which of the following is a need of all living things? A. They need a source of energy. B. They must not go without sleep for more than 4 days. C. They need to receive direct sunlight in order to survive. 13. On a bright, cloudless day, what are three things that can help you tell directions? A.
