钢轨探伤仪37°探头可探测轨腰投影范围内轨底的（）。
A、纵向裂纹
B、水平裂纹
C、横向裂纹
D、核伤
参考答案：C
Mr. Chapman retired at 70 after he _____ nearly 40 years with the Gas Company. [ ]
A. had spent
B. has spent
C. spends
D. would spend
古代埃及和两河流域文字的共同点是
①世界上最早的文字②以符号表示概念和音节③字形逐渐简化④属于字母文字[ ]
A．①②③④
B．①②③
C．①③④
D．②③④
