采煤机的割煤方式有哪些？（） ["双向割煤，往返一刀","“∞”字形割煤，往返一刀","单向割煤，往返一刀","双向割煤，往返二刀"]
Examine the description of the EMPLOYEES table: Which statement produces the number of different departments that have employees with last name Smith?（） ["SELECT COUNT(*) FROM employees WHERE last_name='Smith';","SELECT COUNT(dept_id) FROM employees WHERE last_name='Smith';","SELECT DISTINCT(COUNT(dept_id)) FROM employees WHERE last_name='Smith';","SELECT COUNT(DISTINCT dept_id) FROM employees WHERE last_name='Smith';","SELECT UNIQUE(dept_id) FROM employees WHERE last_name='Smith'"]
新产品投放市场初期，以先高后低的价格策略进入市场，这是（）订价法。 ["取脂","渗透","满意","声望"]
在无人行道的道路路面上空，4m以上允许突出空调机位、窗罩，突出深度不应大于（）m。 ["0.5","1","1.5","2.0"]
CRM的根本作用就是为了（） ["提高市场营销效果","为生产研发提供决策支持","优化企业业务流程","提高客户满意度"]
锆盐—枸椽酸反应
