D
本句的意思是：“即使研究有了新的发展，只有一小部分的试验可以不用动物”。因此答案为D。variety和plenty分别表示“多样”和“大量的”，意思不合适。amount后只能接不可数名词，而test是可数名词。
One of the disadvantages in the Grammar-Translation Method is that the texts are taken from _____, the language of which doesn't often meet the practical needs of the learners.
Asactivitycarried________asonethinksfitinone’ssparetime,leisurehasseveralfunctions.
Thefactory_______we’llvisitnextweekisnotfarfromhere.
Thetwinsisterswereidentical________appearanceandcharacter.
Don’ttrusteverything________youhavereadinthenewspapers.
