The word 'cinch'(Line3, Para.1)most probably means
A．a very easy thing.
B．a very complex thing.
C．a great challenge.
D．an extremely hard problem.

判断题数据的存储结构是数据的逻辑结构在计算机存储器上的实现，它是依赖于计算机的。()

单项选择题绝对优势理论的主要代表人物是()A、亚当.斯密B、大卫·李嘉图C、里昂惕夫D、保罗·萨缪尔森

未分类题It can be inferred from the second paragraph thatA．low-altitude clouds are the main causes of global warming.B．increase of cloud cover can slow down the climate change.C．global warming will increase cloud cover.D．increase of cloud cover can speed up the global warming.

判断题幼儿园的管理层次中，基层为具体工作层，即各班级或班组。()

未分类题The new study published in Science indicates thatA．low-level clouds tend to warm the ocean.B．more cloud cover means a warmer world.C．the warming of ocean is a threat to the low-level clouds.D．the Pacific Ocean has more low-level clouds than before.