题目

空间有一沿x轴对称分布的电场，其电场强度E随X变化的图像如图所示。下列说法正确的是(        ) A．O点的电势最低w w w.ks5 u .c om B．X2点的电势最高 C．X1和- X1两点的电势相等 D．X1和X3两点的电势相等 答案：C 解析: 略 完形填空 　　Canada is the second largest country is the world．It is over 7,000 kilometers from the 　　1　　 coast(海岸)to the east．It 　　2　　 six time zones．　　3　　 it is 9 a．m．in Vancouver on the west coast, it is 1∶30 p.m．in St John’s on the east coast． 　　English and French 　　4　　 the two main languages in Canada．About 60 percent of 　　5　　 people speak English, and about 25 percent speak French．More 　　6　　 70 percent of its population live in cities near the US border(边境)． 　　Ottawa is the capital．Every year millions of tourists go there to 　　7　　 museums and take part in the cultural(文化的)activities．Toronto is the largest city of the country 　　8　　 about 2.5 million people．Montreal is 　　9　　 second biggest French-speaking city in the world． 　　The maple leaf is the national symbol of Canada．The Canadian flag has a red maple leaf on a red 　　10　　 white background． (1) [　　] A． west B． east C． south D． north (2) [　　] A． is B． had C． has D． have (3) [　　] A． Which B． What C． Where D． When (4) [　　] A． are B． is C． will be D． has been (5) [　　] A． their B． his C． its D． our (6) [　　] A． up B． over C． about D． than (7) [　　] A． see B． visit C． look D． find (8) [　　] A． with B． for C． from D． at (9) [　　] A． a B． an C． the D． 不填 (10) [　　] A． or B． and C． but D． however