“立花”由（）个花枝构成。 ["7","8","9","6"]
The main bearing metal is a lining （）. ["inside the bearing","outside the bearing","covering the crankshaft","none of the above"]
国外风险投资的资金来源主要是（） ["公司养老金","公众养老基金","金融机构","慈善机构捐赠基金"]
The machine has stopped rotating because the bearing （） the shaft. ["seized","clogged","melted","inserted"]
烟囱冒黑烟的原因是什么？有什么害处？
火山型张裂边缘的特征如何？
