| accelerate | to speed up, increase the speed |
| arithmetic | n.算术，四则运算 |
| burden | Something that is carried, especially a heavy load |
| conservation | the preservation and careful management of the environment and of natural resources |
| preservation | a process that saves organic substances from decay |
| erect | cause to rise up |
| facility | a service that an organization or a piece of equipment offers you |
| identity | exact sameness |
| massive | consisting of great mass |
| partical | a piece of matter typically an atomic or a subatomic object |