题目

如图所示，假设在某次比赛中运动员从10 m高处的跳台跳下，设水的平均阻力约为其重力的3倍，在粗略估算中，把运动员当做质点处理，为了保证运动员的人身安全，池水深度至少为(不计空气阻力)（ ） A. 5 m B. 3 m C. 7 m D. 1 m 答案：【答案】A【解析】设水深h，对运动全程运用动能定理mg(H＋h)－Ffh＝0，即mg(H＋h)＝3mgh，得h＝5m。故选A。 完形填空 　　In 1896, 17-year-old Einstein went to Zurich for the mathematics and physics program at the Polytechnic in Zurich．There he met Marits, a girl from Hungary and the only woman student in the school．They studied in the same class and the 　　1　　 interest in physics brought the two together and they became good friends．Over the next few years, their 　　2　　 developed into romance．In a letter to her, Einstein called Marits "a creature who is my equal and who is as strong and independent as I am．" In January 1903, when Einstein was 24, he married Marits, who was 4 years older than he． 　　After their marriage, Einstein devoted himself to the 　　3　　 of the great theory of relativity．To give her husband more help, Matits 　　4　　 her own work, and became a good wife and 　　5　　．She tried her best to encourage him whenever possible．She was sure that her husband would 　　6　　．They often discussed the 　　7　　 while walking outside or sitting together in the room．They even did that in their letters when one of them was away from home． 　　In 1904, the Einsteins moved to Berlin and 　　8　　 there．At that time, Einstein's theory 　　9　　 to be correct and he became 　　10　　 all over the world．Marits was very 　　11　　 her husband with his success．But it was not long before the First World War 　　12　　, Marits as well as her two sons, who were 　　13　　 in Switzerland, couldn't come back to 　　14　　 any longer．The war not only stopped Einstein's work but also broke up the warm, happy 　　15　　．In 1919, Einstein and Marits had to get divorced, having lived apart for five years． (1) [　　] A． great B． special C． common D． especial (2) [　　] A． membership B． ownership C． relationship D． friendship (3) [　　] A． cause B． matter C． idea D． research (4) [　　] A． gave up B． held up C． gave in D． took off (5) [　　] A． mother B． cook C． servant D． assistant (6) [　　] A． agree B． practise C． succeed D． accept (7) [　　] A． plan B． program C． suggestion D． theory (8) [　　] A． put away B． lived C． settled down D． worked (9) [　　] A． seemed B． appeared C． looked D． proved (10) [　　] A． excited B． famous C． satisfied D． lucky (11) [　　] A． proud of B． admired for C． surprised at D． worried about (12) [　　] A． ended B． broke out C． finished D． took place (13) [　　] A． living B． working C． traveling D． performing (14) [　　] A． Berlin B． Munich C． Hungary D． Switzerland (15) [　　] A． life B． time C． home D． family