三糖铁培养基与双糖铁培养基的区别在于加与不加()。
A.乳糖
B.葡萄糖
C.蔗糖
D.枸橼酸铁
E.山梨醇
参考答案:C
生物标志在环境流行病学中可应用于()。
A.生物有效剂量的测量
B.内剂量的测量
C.早期效应的测量
D.宿主易感性的评价
E.以上都是
Fragments of charred antelope bone have recently been found at a million-year-old settlement of Homo erectus, an early human species. This discovery demonstrates that humans were making controlled use of fire to cook meat at a very early stage of their development. The argument above makes which of the following assumptions
A.Every human species since Homo erectus has made controlled use of fire.
B.Homo erectus could not have eaten antelope meat unless the meat had been cooked.
C.Early human settlements can be identified by the presence of charred antelope bones.
D.The diet of Homo erectus consisted in large part of antelope meat.
E.(E) The antelope bones were charred in a fire controlled by humans.