7、【答案】 D 细节理解题。由Movingatlightningspeed,hugewallsofflamescanburnacresoflandinjustafewminutes.Andalthoughtechnology,includingtheuseoffire-retardantchemicals,hasgreatlyhelpedthefightagainstforestfires,theystilldogreatdamage.可知森林火灾被认为是最令人害怕的,是因为它们蔓延得太快,造成的损失太巨大,选D。2.Al
8、most25%forestfiresareset____.A.unexpectedlyB.bylighting C.onpurposeD.naturally【答案】 C 细节理解题。由Almostonequarterarepurposelyset,whilelightingcauses10%.可知几乎25%的森林火灾