因偶然波动和异常波动引起质量变异,下列说法中正确的是()
A、偶然波动可以避免
B、偶然波动不可避免
C、采取措施不可以消除异常波动
D、采取措施可以消除异常波动
参考答案:B, D
Silk from China found its way to India, the Middle East and Rome, _______ spices and glass, which was not known to China.
A.in exchange for
B.in return
C.in change for
D.in need of