YSP4.7型钢瓶，允许最大充装重量为（）㎏。 ["4.7；","1.9；","2.0；","2.5"]
我国家庭农业生产规模很小，全国平均每户承包土地（）亩左右。
食品中的植物性毒素主要有哪些？
在小学课堂教学中，教师对于表现优秀的小组给予小花红奖励。这种教学效应最适合的心理学解释理论（） ["强化说","认知失调论","从众说","观察学习理论"]
Due to slow response times， a customer purchased additional memory. After the memory was installed，response time was not improved. They complained to the pSeries technical specialist. Which of the following questions should be asked of this customer？（） ["Who recommended the memory purchase？","Have more users been added since the memory purchase？","Why were additional CPUs not ordered at the same time as the memory？","Did a performance analysis of peak periods show a memory bottleneck？"]
请简述Switch变流系统中,变流器发电机侧空开闭合测试步骤
