If we________develop the world successfully, we must make sure that everyone is able to take part in the new world we create.

A．are about to

B．are going to

C．are to

D．will

电焊条的质量直接影响焊缝的性能，电焊条由钢芯和药皮组成，药皮应根据工艺要求选用，重要结构用（）焊条。

A、酸性

B、碱性

C、中性

D、工艺加工