价值工程的主要特征着眼于提高价值，即以( )实现必要的功能。

A．产品的合理成本

B．产品的最低成本

C．产品的研制、生产费用

D．最低的寿命周期成本

The ancient penguin was     modern ones and it was good at swimming but couldn’t fly.

A．as large as twice

B．larger than twice

C．twice the size of

D．twice as larger as