参考答案:答案解析:To realize the development goals, China has adopted a new concept of development in line with its na
气硬性胶凝材料只能在空气中硬化,也只能在空气中保持或继续发展其强度。水硬性胶凝材料不仅能在空气中硬化,而且能更好的在水中硬化,并保持和继续发展其强度。
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