正等轴测图的轴间角为()。
A.45°
B.60°
C.90°
D.120°
参考答案:D
The girl often helps the old man _____ water.[ ]
A. carrying
B. carry
C. carries
D. carried
《地面气象测报质量考核办法》规定:气压自记纸的读数误差()的算一个错情。
A.≧0.1
B.≧0.3
C.≧0.5
D.≧0.6