spECiFiCAlly EquippED plAnEs hAvE BEEn usED ______.
A．to sprEAD ChEmiCAls ovEr thE ForEst nEAr mosCow Airport
B．to sprEAD ChEmiCAls ovEr thE plAnEs to DEAr thE Fog ArounD thEm
C．to sprEAD ChEmiCAls ovEr thE Fog lo hElp CrEAtE "winDows" in thE Fog For plAnEs to lAnD AnD tAkE oFF
D．to sprEAD ChEmiCAls ovEr thE runwAy At mosCow Airport