在如下图所示的食物网中，已知各营养级之间的能量转化效率为10%，若一种生物摄食两种上一营养级的生物时，两种被摄食的生物量相等，则丁每增加10千克生物量，需消耗生产者戊多少千克？（）
A. 3250kg
B. 4500kg
C. 4750kg
Whatindicatesthatatropicalcyclonemaybewithin500to1，000milesofyourposition?（）
Apumpingofthebarometerupanddownafewmillibars
B. Asuddenwindshiftfromsouthwesttonorthwestfollowedbysteadilyincreasingwinds
C. Thenormalswellpatternbecomingconfused，withthelengthoftheswellincreasing
D. Anovercastskywithsteadilyincreasingrainfromnimbostratusclouds
Are-heaterinanairconditioningsystemfunctionsto（）.
A. controlinletairtemperature
B. controlinletairvolume
C. maintainrelativehumidityat15%
D. restoreconditionedairtemperaturetoacomfortablelevel
Whenadeckcargoissecuredwithchainorwirelashingsandgrab(pear)links，whichstatementisFALSE?（）
A. Theamountoftake-upislimitedbythelengthoftheturnbuckle
B. Atthegrab(pear)link，theslackendofchainshouldbeledbackandsecuredtothechainabovethelink
C. Thelashingsshouldbeinspectedeachdayandanyslacktakenup
D. Theturnbuckleshouldbesecuredwithastickorlocknuts
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