شرکت در آزمون آنلاین
انگلیسی 3
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درس سوم
| آزمون شماره 11812
The company is also developing new ......... which it hopes will be strong enough to fill cavities in the back teeth.
The gases, especially carbon dioxide and methane, ......... the Earth’s heat radiation and thus warm the surface, just as a blanket traps body heat.
