闸门（）等装置外观检查时，应注意焊接应力区是否有异常。

A、焊缝

B、臂杆

C、支撑

D、吊耳

E、锁定

When the Erie Canal was built in the 1820's, it was the engineering marvel of its time.

A．wonder

B．dispute

C．frustration

D．model