[单选题]保安服务主要依据合同的约定或根据自行招用保安员单位的要求,履行客户单位及服务区域内秩序维护、保护()安全等职责。
A.守卫对象
B.人员设备
C.单位内部
D.人身及财产

Cryptic species animals that appear identical but are genetically quite distant--may be much more widespread than previously thought. The findings could have major implications in areas ranging from biodiversity estimates and wildlife management, to our understanding of infectious diseases and evolution.
Reports of cryptic species have increased dramatically over the past two decades with the advent of relatively inexpensive DNA sequencing technology. Markus Pfenninger and Klaus Schwenk, of the Goethe-Universitat, in Frankfurt, Germany, analyzed all known data on cryptic animal species and discovered that they are found in equal proportions throughout all major branches of the animal kingdom and occur in equal numbers in all biogeographieal regions.
Scientists had previously speculated that cryptic species were predominantly found in insects and reptiles, a
A. They occurred in equal numbers in all biogeographical regions.
B. They were mostly found in insects find reptiles.
C. They were likely to be in tropical rather than temperate regions.
D. D. Both B and