端粒酶(telomerase)
参考答案：
是由RNA和蛋白质组成的核糖核蛋白复合物(RNP)，可以自身RNA为模板，复制合成丢失的端粒序列。
关于东西半球的叙述，正确的是 [ ]
A．东经度的范围都在东半球
B．本初子午线和1800经线是东西半球的界线
C．1800经线在东半球
D．200W—00—1600E的经度范围为东半球
Project X has an internal rate of return (IRR) of 14%. Project Y has an IRR of 17%. Both projects have simple cash flows (all positive after the initial one). Which of the following statements is most likely correct If the required rate of return is:（）
A. 14%, the net present value (NPV) of Project Y will exceed the NPV of project X.
B. less than 17%, Project Y will always have a shorter payback than Project X.
C. greater than 17%, Project Y will always have a shorter payback than Project X.
