If you want to have a scientifically valid sample for a for a study you are doing, which of the following conditions must be met? choose all that apply a. a group that includes people who are convenient to use b. a random sample c. a sample that includes the population you are studying d. a group of volunteers

The table presents the average day and night temperatures in five cities. it also reveals whether a city receives substantial rainfall (wet climate) or little rainfall (dry climate). which city’s rocks are likeliest to experience frost wedging, and why? a) city a because the consistently subzero temperature would prevent water from melting b) city b because it is a wet region and the temperature fluctuates around the freezing point c) city c because it receives plenty of rain fall and the weather is moderately cool d) city d because the hot and dry weather would cause rocks to absorb water