You see a woman standing in front of school, now and then stopping students to
ask them questions. She says she is
collecting student opinions for the
newspaper. This is an example of:
A. A convenience sample
B. A self-selected sample
C. A systematic sample
D. A random sample

Ineed with number 17 i don’t get it at alll

What are potential hypotheses (explanations) regarding why there are ecological equivalents between many metatherians and eutherians? discuss your hypothesis in terms of the processes that could lead to the current ecologies and distributions of metatherians and eutherians.

Ascientist wants to use a model to present the results of his detailed scientific investigation. why would a model be useful? a )because the model makes the concepts easier to understand b) because the model is easy to put together and to use c) because the model prevents other scientists from asking questions d) because the model requires the audience to pay full attention to it i don't know what to choose because between a and d a is much more likely than d because it only wants to get the attention of the audience. i'm confuse.