During the early years of hardwired NC, built-in diagnostic tools existed.
举一反三
- The first primitive man known to have existed in China is ( ), who lived about 1.7 million years ago. ( ),who existed more than 600,000 years ago at Zhoukoudian, in the vicinity of modern Beijing, could walk upright, make and use simple tools, and make use of ( ) .
- Chinese had mastered the technology of smelting bronze approximately 5,000 years ago and iron tools came into use during the ___________.
- During the early years of Eastern Han Dynasty, the complete twenty four solar terms came into being.（ ）
- An important advance in the philosophy of NC of machine tools was the shift toward the use of controller units instead of computers in NC systems.
- The factory ________ last year, and that one was built many years ago. A: was built B: build C: built