Which of the following is an example of how science can solve social problems? it can stop excessive rain from occurring. it can identify the sources of polluted water. it can control the time and day when cyclones happen. it can reduce the frequency of severe weather conditions.

It can identify the sources of polluted water.

Scientific innovations and researches have been proved to be beneficial in solving the day to day social problems such as household practices such as cooking, washing of cloth, industrialization and conservation of the environment.

It can identify the sources of polluted water is the correct example of how science can solve social problems. The source of pollution can be identified by tracing back it's origin and application of filters and purifiers can help in controlling the pollution.

1. the question asks the most appropriate, which seems to rule out "all of the above." your choice appears to be the correct one.

2. the protocol described is good for identifying correlation, but not cause and effect. for cause/effect, you need to devise a protocol that will assign the treatment (or not) to groups that have essentially the same "demographics" with respect to all the other variables. your choice regarding control group seems appropriate. random assignment of treatment (choice d) may be appropriate also. (i think you can argue that b and d are just different descriptions of the same method.)

3. d will randomize the birds, but may not guarantee there are 10 in each group. e will do both, so seems the better choice.

comment on question 2

based on the problem statement, it seems clear that confident, attentive drivers are more likely to use daytime running lights. so, the protocol might need to be devised in such a way that the lights would be turned on or off without the driver's knowledge. (an attentive driver will figure it out.) assigning a confident, attentive driver to a group required to drive without running lights might mess with his/her confidence and attentiveness. you don't want your experiment to do that. (nor do you want the experiment to subject a driver to greater risk of accident as a consequence of driving without running lights.) experiments involving human safety are always problematic.

the answer is option a.