Animal echolocation extremely narrow beams and many receivers to localize a target (multibeam sonar), animal echolocation has only one transmitter and two receivers (the ears) positioned slightly apart. The echoes returning to the ears arrive at different times and at different loudness levels, depending on the position of the object generating the echoes. The time and loudness differences are used by the animals to perceive distance and direction. With echolocation, the bat or other animal can see not only where it is going but also how big another animal is, what kind of animal it is, and other features.. At the most
None Is Too Many authors identify Frederick Blair, the head of immigration in William Lyon Mackenzie King's government, as a top official who opposed and limited Jewish immigration. They say that Blair's policy had the full support of Mackenzie King, who was prime minister 1935–48, Vincent Massey, the high commissioner to Britain, and both Anglophone and Francophone elites in general. The title is based on an incident recounted in the book. Early in 1939 an unidentified immigration agent was asked how many Jews would be allowed in Canada after the war. He replied ""None is too many"". The phrase has since entered common parlance