化学镀镍是利用镍盐溶液在还原剂磷酸盐的作用下,使镍离子还原成镍金属。
参考答案:错
(2013·江苏南通市二模)We ________ have hurried all the way to the airport — the flight was called off because of the foggy weather.
A.mustn't
B.couldn't
C.needn't
D.wouldn't
白喉毒素