Oh past exam just means exams from past years. The one that I'm doing now is the 2010 exam on ethics and religious studies. Students usually do past exams as mock exams to prepare for the actually exam.
About myself, actually it's a little more complicated. I already graduated high school and am applying for a police constable position. The police department requires all candidates to pass a written test in which it includes questions about social, political, ethical, and religious topics. And so I went to the library and borrowed some past high school exams just to do some practice on writing and answering questions on these topics. No idea if the questions on the tests will actually be similar to those of high school exams though lol.
Ah.
Well, to answer your OP, the message, "Drugs are bad" that's been hammered into our heads is a current iteration of an interesting history involving a waxing and waning of approval of various substances (for example, opium, cocaine, tobacco, the prohibition) with different cultural stories and tipping points for each substance. Some societies used certain drugs to facilitate meditation and religious experiences, and they used drugs
only during these rituals. In today's money-driven culture, anything which decreases productivity in our culture is disapproved of (with the exception of alcohol, strangely, though that has a story, too).
To legislate drugs on par with their risk factors would require legislative changes which won't happen unless cultural attitudes change. I suspect cartels are very, very supportive of keeping drugs illegal and funnel a lot of money into anti-drug educational campaigns, which helps maintain the mythological status drugs have earned. After all, if a black market substance become legalized, the black market movers lose their economical power.
So the ethicality of taking drugs involves weighing the risks of legal consequences, being informed and educated about the substance itself and where it was obtained, and weighing the risks and benefits of the drug.