The conclusion
explanation- i learned that before
the answer is d they requiere fire resistant material
Explanation: they all deal with fire and heat
Reassureverb [ T ] C1 to comfort someone and stop them from worrying: [ + to infinitive ] I was nervous on my first day at college, but I was reassured to see some friendly faces. [ + (that) ] He reassured me (that) my cheque would arrive soon.
Answer:
<em>The altitude of the cloud cover is called the</em> ceiling <em>in</em> aviation<em>; it is an important measurement for those piloting small planes.</em> As for the other question, I only know that the second part is international.
Explanation:
ceiling: the upper inside limit of a room; also the height above the ground of the lowest clouds.
aviation: the operation of aircraft.
international: beyond the boundaries of a single nation.