质量员应坚持“预防为主”的方针，经常组织定期的（）活动。
A、工程验收
B、回访保修
C、质量检查
D、技术复核
参考答案：C
My brother bought a teapot ________ like a Chinese duck, the price of which was much lower than expected.
A．shaping
B．being shaped
C．to be shaped
D．shaped
螺杆式制冷压缩机属于容积型的制冷压缩机，有单螺杆和双螺杆两种。
