One protective measure to prevent asphyxiation is that the gas is a) odorized, so it can be smelled b) colored, so it can be seen c) automatically turned off before it can escape d) kept in safe canisters that cannot be penetrated

the answer is:

in a biology class, the teacher started explaining a new lesson about the dna structure. personally, i found this lecture hard to understand. so i decided to use my critical thinking skills to be able to understand it. i analysed the different ideas, and broke them down into smaller parts to assimilate each. then i started evaluation and tried to link what i am learning with real life experiences so that i can make sure that i know how everything i am learning relates. finally, i started questioning by researching more what i learned and asking more questions that can me through my learning process. reflecting on the information meant that i should review it. all this me greatly understand what i previously found hard to understand.

hope it !