In the original test，all the animals in a test group are given a substance _______ half of them die
A、unlessB
本题考查词义辨析。until：直到。符合句意，表示givenasubstance持续到halfofthemdie。
“Thedignityofmovementofanicebergisduetoonlyone-eighthofitbeingabovewater.”This“iceberg”analogyisputforwardby().
MostliterarycriticsthinkthatFitzgeraldisbothaninsiderandanoutsiderof()withadoublevision.
InGoDown,Moses,()illuminatestheproblemofblackandwhiteinSouthernsocietyasacloseknitdestinyofbloodbrotherhood.
In1950,oneoftheleadingAmericanwriters()wasawardedtheNobelPrizefortheanti-racistIntruderintheDust.
Theattitudetowardslifethat()hadbeentryingtodemonstrateinhisworksisknownas“graceunderpressure”.
