酸洗槽中硫酸的浓度和温度均满足工艺要求，但酸洗速度较慢，其原因是（）浓度偏高。 ["Fe","Fe2+<\/sup>","Fe3+<\/sup>","以上均不是"]
政府如何构建更加高效的科研体系？（） ["优化对基础研究的支持方式","加强市场性评价模式的研究和探索","明确不同类型科研院所的定位","完善科研资金的审计制度"]
新闻传播的要素主要包括（）。 ["事实","新闻报道者","新闻接受者","新闻效果","新闻教育"]
Given： 310-025 Leading the way in IT testing and certification tools， www.testking.com - 48 - public class foo { static String s； public static void main （Stringargs） { system.out.printIn （“s=” + s）； } } What is the result？（） [" The code compiles and “s=” is printed."," The code compiles and “s=null” is printed."," The code does not compile because string s is not initialized."," The code does not compile because string s cannot be referenced."," The code compiles， but a NullPointerException is thrown when toString is called."]
将矿石加热分解变成磁铁矿的焙烧方法是（）焙烧。 ["中性","氧化","还原"]
简述证据规则有哪些？
