GJ-4车检测线路所运用的测量原理是（）。
参考答案：轨距检测原理
With the ______ of making a fortune,many people went to Australia in the 19th century to wash sand
for gold. [ ]
A. task
B. intention
C. trade
D. appointment
下列四幅热力环流图中，画法正确的是（）
A、①
B、②
C、③
D、④
