（）是静电涂装的动力，它的强弱直接影响静电涂装的效果。
参考答案：电场强度
Progress so far has been very good. _____, we are sure that the project will be completed on time. [ ]
A. However
B. Otherwise
C. Therefore
D. Besides
425+683+544+828的值是( )
A．2480B．2484C．2486D．2488
