Word came from California of a new weapon in the war on household pests．Two scientists work for a firm in California developed 1．__________3 D3 ]! v0 o# J' D6 U* \0 D/ ]
a new method to eliminate insects with using dangerous chemicals．The new 2．__________
v2 y: m5 P$ e) k8 G4 E: m2 T: Y weapon—hot air．The basic idea is that insect pests can adjust to temperature much above 3．__________: l: P; \7 }5 q! o1 p( t
normal． In laboratory experiments，cockroaches and termites can’t survive much more than a quarter of hour at 100 degrees 4．__________( ?+ }. V0 T2 L# o4 n
Fahrenheit or about fifty degrees centigrade． The new method involves covering a house with a huge tent，and fill it with air heated to 5．__________
5 _+ m, h; i g, _$ i1 h around 65 degrees centigrade．Hot air is forced in with fans and the tent keeps the heat inside the house．Although termites try to escape by 6．__________, C: [+ w5 r( f& D5 I
hiding in wood beams，the heat treatment must be continued by four to six hours．But when it's 7．__________* N# N1 Q0 b' V1 W) ^" h; H
all over and the insects are dead， there are no toxic residues to danger humans or pets，and no 8．__________1 q0 a1 ~& C! s0 P4 B* m- ^
funny smells．Scientists claim that there's no danger of fire too． 9．__________
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发表于 2012-8-14 09:52:33
