Carlos and Matt were in science class studying friction. They began their investigation by pulling a block across their wood desk and recording the force needed to slide the block a distance of .5 meters. The boys hypothesized that is would take more force to pull the block across the desk if it were covered with cardboard. They repeated their original procedures, but with cardboard on the desk, under the block. To their surprise, the about of force to move the block .5 meters was the same! What would you tell the boys about their hypothesis and results? A) The hypothesis was incorrect and the design was flawed. B) The hypothesis was not a good one because it was not supported by their results. C) The hypothesis was not supported; the amount of force to move the block was the same on cardboard. D) The hypothesis was not supported; the boys should repeat the experiment until they get the results they predict.

Next pretest: evolution select the correct answer in a laboratory population of flies, the female flies are gray and the males are yellowish gray. biologists observed that all the male flies had an equal chance for reproduction, but the male flies with the brightest colors were more likely to successfully reproduce. what phenomenon could explain such a change? a sexual selection b. disruptive selection c. stabilizing selection d. directional selection

Complete the sentences by matching the names of trees to the appropriate blanks. to do this, drag the names on the left into the appropriate blanks in the sentences on the right. match the words in the left column to the appropriate blanks in the sentences on the right. terms may be used more than once. make certain you have filled every blank with a term before clicking submit. 1. deciduous trees lose their leaves seasonally and include trees such as maple and elm. 2. conifer leaves are generally thin and needle-like, while seeds are contained in cones. conifers include cedar and pine. 3. evergreens are plants that maintain their leaves in all seasons and include trees such as cedar, elm, and pine. 4. hardwoods reproduce using flowers and have broad leaves; hardwoods include trees such as maple, , and cedar. elm returned you filled in 2 of 10 blanks incorrectly. mango trees are tropical broad leaf plants that maintain their leaves all year long. no credit lost. try again.

Select three sports that require participants to be highly fit before the beginning a: snowboarding b: skydiving c: rock climbing d: bungee jumping e: free diving f: hiking