I believe it's the last one "<span>Scientists studied the trapping of gases in the atmosphere."</span>
Question 1 is C/ Question 2 is A/ Question 3 is B / Question 4 is A , I hope that’s right
The substitution of the name of an attribute or adjunct for that of the thing meant, for example, suit for<span> </span>the business executive<span>, or </span>the track<span> for </span>horse racing<span>.
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