A researcher wants to do a web-based survey of college students to collect information about their sexual behavior and drug use. Direct identifiers will not be collected; however, IP addresses may be present in the data set. Risk of harm should be evaluated by:both magnitude and probability of harm
both magnitude and probability of good

Both the magnitude( severity ) and the probability (or likelihood ) of harm  

Explanation:

A web survey is called an internet survey that is used to collect information about the subjects or collect the data through the internet. In this process, the researcher sent a questionnaire to the respondent on the internet.

Through the internet, they can collect data over the world. The respondent can be sent their respondent through the internet, mails, website, and social media.  

This is the best way to collect information at a big level.

c. taught scientists many new things about the earth, but not other planets.

explanation:

muslims have taken his goods and products to different parts of asia an indonesia. sometimes just traveled and trade, but in other occasions, stayed in the place and made a living.

trade was the key for muslims economies to prosper. their commerce routes reached far places like malaysia and java in the 11th century.

another important factor for prosperity was that muslim states served as the middle point for european traders.

they used to travel by land but sailing the seas -the indian ocean- really increase the exportation of products.