[填空题] 在三种北京人中，（）和曾瑞贞可以看作从现实北京人走向未来北京人的代表。

我国渔业生产方针是什么？ Click the Exhibit button and examine the data in the EMPLOYEES and DEPARTMENTS tables. You want to retrieve all employees, whether or not they have matching departments in the departments table. Which query would you use?（） ["SELECT last_name, department_name FROM employees NATURAL JOIN departments;","SELECT last_name, department_name FROM employees JOIN departments ;","SELECT last_name, department_name FROM employees e JOIN departments d ON (e.department_id = d.department_id);","SELECT last_name, department_name FROM employees e RIGHT OUTER JOIN departments d ON (e.department_id = d.department_id);","SELECT last_name, department_name FROM employees FULL JOIN departments ON (e.department_id = d.department_id);","SELECT last_name, department_name FROM employees e LEFT OUTER JOIN departments d ON (e.department_id = d.department_id)"] 交易费用 请选出下列组件中，哪个属于非可视的组件？（） ["按钮（Button）","标签（Lable）","计时器（Timer）","数据源（DataSource）"] 基本模数是模数协调中选定的基本尺寸单位，其符号为M，数值为（）。 ["10mm","100mm","1000mm","10000mm"] 在三种北京人中，（）和曾瑞贞可以看作从现实北京人走向未来北京人的代表。