The presence of which feature in a study is sufficient to classify it as experimental?
a) a control group
b) a random sample
c) none of the features
d) quantitative variables

Study the diagram of a cell. which structure is found only in plant cells and functions in the process of photosynthesis? w x y z

1. seamount a raised footwall block between normal fault creates this 2. syncline break between rocks where a hanging wall rises relative to a footwall 3. hot spring on rolling hills, this a dip between hills 4. volcanic neck created when a block with hanging walls slips down between normal faults 5. caldera underwater volcano that never reaches above sea level 6. horst natural hot water on earth's surface containing many minerals 7. graben underwater volcano whose top is eroded flat by waves 8. crater less than a mile in diameter; looks like a bowl at the top of a volcano 9. guyot magma that filled the central vent that remains after the volcano has eroded 10. reverse fault over 1 mile in diameter; looks like a bowl over a volcano

Which of the following is a limitation of a clinical trial? a.)amount of random assignments b.)hospital cost c.)number of test tubes d.)amount of peer review