[FIXME] In the following code, find three errors or problems that will cause security issues (e.g., buffer overflow) or reliability issues (e.g., crash, significant slowdown) at runtime. For each error or problem, use one sentence to describe the error or problem (also list the line number), and use one sentence to  describe your fix. No syntax issues. [4 X 3pts]    

The kernel space runs on the ring 3 privilege level, and the user space runs on ring 0.

Under the CDECL (32 bit) calling convention, function arguments are passed through registers.  

The return value of a system call should be checked, as the system call may fail

By introducing authority in the authentication, we can prevent confused deputy attacks.

[Short-answer question] Out-of-bound read and write are spatial memory errors, and use-after-free and uninitialized uses are temporal memory errors.Memory safety techniques can prevent such memory errors in principle. However, why are memory safety techniques not adopted in practice yet? Think about the criteria for evaluating a defense mechanism.

Imagine that the Environmental Protection Agency has asked you to propose a health impact assessment (HIA) of an emerging air pollutant in the United States. Please outline how you would approach this HIA (4 sentences minimum). Your answer should include: Which emerging air pollutant would you study and why? What population and health effect(s) would you be investigating? What pieces of information/data would you need to conduct your HIA? What kinds of interventions (any amongst the hierarchy of controls) might be feasible to reduce risks from this pollutant?

An epidemiologist is analyzing asthma case data for three states and find these results: State A: Population of 5 million, with an asthma rate of 8 per 1,000 people. State B: Population of 2 million, with an asthma rate of 12 per 1,000 people. State C: Population of 1 million, with an asthma rate of 10 per 1,000 people. What is the overall weighted average asthma rate (per 1,000 people) across all three states? (select one) What is the correct term to describe this rate? (select one)

Categorize the air pollution sources as stationary or mobile.

Provide an appropriate response.Assume that blood pressure readings are normally distributed with a mean of 121 and a standard deviation of 6.4. If 64 people are randomly selected, find the probability that their mean blood pressure will be less than 123.