铀是常用的一种核燃料，若它的原子核发生了如下的裂变反应：，则a+b可能是

A．

B．

C．

D．

UML-based tools are often used for J2EE/.NET application analysis and design, both because UML’s object orientation is ideal for the J2EE/.NET implementation (66) and because of the expanding scope and complexity of today’s enterprise endeavors. (67) the approaches diverge at the coding/implementation phase, a common set of analysis and design techniques applies to both J2EE and.NET.

The use of a virtual, machine (VM) architecture is also common to J2EE and .NET. Application development tools (68) intermediate-level code instead of platform-specific binary code, which means the VM interprets that code in real time or performs Just-In-Time (JIT) compilation; the Microsoft VM always runs JIT-compiled code. This VM-based model results in (69) -independent applications and is conducive to the late-binding technique that’s (70) to the OO approach.

（66）（）

A.block

B.model

C.module

D.group