LF炉采用()加热可加热钢液,调整温度,并在高温下熔化精炼渣。
参考答案:电弧
Although she has a lot of problems,she manages to remain ________.[ ]
A.optimistic
B.cautious
C.concerned
D.anxious
采用十进制,就有55种求和与求积的运算规则;而二进制仅有3种。