搜题请搜索小程序“爱下问搜题”
问题 实验题

在测小石块的密度的实验中，小明先用天平测小石块的质量（如图甲所示），小石的质量是　     g，再用量筒测小石块的体积（如图乙所示），测小石块的密度ρ1=　      kg/m3；小丽做实验时，先用量筒测小石块的体积，再用天平测小石块的质量，测得的小石块的密度为ρ2，则ρ2　     ρ1(选填“＞”、“＜”或“＝”)．

答案

24 ；4.8×103；大于

题目分析：用天平测量物体质量时，所测物体的质量等于右盘所有砝码质量之和加上游码指示的质量值，由图甲知所测小石块的质量为m=24g，再由图乙知所测小石块的体积为V=5cm3，则小石块的密度ρ1=m/V=24g/5cm3=4.8g/cm3=4.8×103 kg/m3；实验时，若先用量筒测小石块的体积，再用天平测小石块的质量，由于小石块表面粘有部分水，使质量的测量值偏大，故测得的小石块的密度为ρ2＞ρ1。

单项选择题

纵隔摆动发生于（）

A.开放性气胸

B.胸壁塌陷

C.张力性气胸

D.多根多处肋骨骨折

E.单纯性肋骨骨折
查看答案
填空题

Bill Gates receives honorary knighthood


Britain’s Queen Elizabeth stands with Microsoft chairman and philanthropist Bill Gates after presenting him with an honorary knighthood at Buckingham Palace, London, March 2, 2005.
Sir Bill Not quite. Proclaiming himself "humbled and delighted," Microsoft founder Bill Gates received an honorary knighthood Wednesday from Queen Elizabeth Ⅱ—an accolade that allows the recipient to use "KBE" after his (1) , but not to put "Sir" in front of it.
One of the world’s richest men, Gates, 49, was (2) honored for his charitable activities around the world and his contribution (3) enterprises in Britain.
Past recipients of the honorary knighthood (4) from Irish singer Bob Geldof to former U.S. President Ronald Reagan.
"This (5) is particularly poignant given the deep connections Microsoft enjoys (6) the United Kingdom," said Gates, whose company employs about 2000 people in (7) .
Gates’ royal honor—bestowed by the queen on the advice of the (8) —was announced in January 2004, but a "mutually convenient" date to (9) it had not been available until now.
British recipients of knighthoods are entitled to be (10) with a "Sir" before their names. The honor was long the (11) of senior soldiers, judges and other servants of the state, but recent years have seen the creation of Sir Paul McCartney, (12) Mick Jagger and Sir Elton John.
As an American, Gates is not entitled to use (13) before his name, but he can put the initials KBE—Knight Commander of the (14) Empire—after his name.
Gates joins a roster of American (15) that includes former presidents Reagan and George H.W. Bush, comedian (16) Hope, retired U.S. Army Gen. Tommy Franks and former Secretary of (17) Colin Powell.
Gates said he was proud of what he called (18) "special relationship" with Britain.
"The U.K. was the first country in (19) Microsoft set up a subsidiary outside the U.S., and our experience in the (20) has been significant in shaping our international growth," he said.
Microsoft’s British facilities include Research Cambridge, a laboratory established in 1997 in the university town that employs 80 scientists. In 2000, the Bill & Melinda Gates Foundation announced a donation of $210 million to Cambridge University to create a scholarship program for graduate students from outside Britain.
查看答案