从 1,2,3,4,5,6 这六个数字中等可能地有放回地连续抽取 4 个数字，则事件“取得 4 个数字完全不同”的概率为_______。

连续2011个“1”异或的结果是__。

逻辑变量X与1异或结果是（），与0异或的结果是（）。

If a boy or a girl has grown up in a home with sharing tasks and decisions，he or she will probably______.

Either he or I ______to the airport.

Duty is an act or a course of action that people __________you to take by social customs, law or religion.

Duty is an act or a course of action that people ______you to take by social customs, law or religion.

Project ______is an uncertain event or condition that，if it occurs，has a positive or a negative effect on at least one project objective，such as time，cost，scope，or quality．

It will be a relief over the death of a friend or a relative if the friend or relative dies from ______.

Hurry up, or you ______ catch the train.

逻辑运算符（AND、NOT、OR）的运算顺序是AND→OR→NOT。

逻辑运算符（AND、NOT、OR）的运算顺序是AND→OR→NOT。