荧光渗透探伤法和着色渗透探伤法在原理上主要区别是使用的颜料和观察方法不同。
参考答案:对
根据图片内容补全对话。
小题1:
—________ is he?
—_________ is Xiao Ming.
小题2:
—Is she _________ Japan?
—No, she _________.
小题3:
— _________ are they from?
—They are from ____________.
小题4:
—___________ are you?
—___________ ,thanks.
小题5:
—___________ she Jane?
—___________, she is.
铁的冶炼技术和铁器的诞生是()的标志。