Abbreviations are very useful in practical work. Read them and then translate them into corresponding Chinese terms. 1. CMI Computer Managed Instruction 2. CRS Cold-rolled Steel 3. CS Complete Self-protecting 4. CO. NI. Copper Nickel Alloy 5. DC Direct Current 6. DC rel. Direct Current Relay 7. DME Distance Measuring Equipment 8. DP Difference of Potential