In 1972, the United Nations hold a meeting in Sweden   小题1:_________            

to share ideas about ways to take better care of for the           小题2:__________

earth．At the summit, people from more than one hundreds           小题3:__________

countries discussed some of the important problems faced           小题4:__________

our planet．Since then, several Earth Summits had been held.       小题5:__________

In 2002, the Earth Summit was held in Johannesburg.            小题6:_________

One of the main theme was “sustainable development”, or     小题7:__________

the question what we can continue developing the world         小题8:__________

without damage the environment．Most of the speakers           小题9:__________

talked the three biggest killers in the world.                     小题10:__________

在软件生命周期中，( )阶段的工作量最大，大约有70%。

A．维护

B．编码

C．测试

D．初步设计