如图所示，在圆形区域内，存在着垂直纸面向外的匀强磁场，ab是圆的一条直径。一带电粒子从a点射人磁场，速度大小为vo，方向与ab成30°时，恰好从b点飞出磁场，粒子在磁场中运动的时间为t。现将粒子的速度大小减为，方向不变，则粒子在磁场中运动的时间为（不计带电粒子的重力）
Downs, Elizabeth
例4.-Who are the men over there?-They are C fathers. They are both teaching English in our school. A. Mike and Jack B. Mike and Jack's C. Mike's and Jack's D. Mike's and Jack 相关知识点: 试题来源: 解析 答案见上解析考查名词所有格的用法。句意:——那边的男人们是谁?——他...
Who give us life, raise us and are our constant support and well-wishers? Our mothers. That's why millions of people across the world take Mother's Day as an opportunity to express thanks and send best wishes to their mums.However, the celebration of Mother's Day is not the recent thi...
"Fathers Are Very Important, but They Aren't Our Contact Persons": The Primary Contact Person Assumption and the Absence of Fathers in Social Work Interven... Research on the engagement of fathers in family- and child-oriented social work interventions has focused on individual factors relating ...
Today's dads come in many shapes and sizes; many of us are still the primary breadwinner in the family, but most of us place much greater emphasis on family than our counterparts in previous generations, including our own fathers. On the one hand, that represents progress from a time not...
根据第1段Most of us have the same family name as our fathers.(我们大多数人都和我们的父亲有相同的姓氏。)可知,我们大多数人的姓是从我们的父亲那里得到的。故选A。(2)细节理解题。根据第1段In some societies,however,both family names and property(财产)are passed down from ...
how friendly their r fathers spen d with t fathers are hem C. how well their fath D. how friendly they a ers get on with their r e with their parents mothers【小题3】 T h e underline d word"astounded" in th e passag e means C . surprise A. sad B. pleased D. upset d【小...
【题目】Sons who have fon d childhoo d memories o f their fathers are more likely to be emotionally s table in the face o f day-to-day stresses, according to psychologists who studie d hundreds o f adults o f all ages. "As our study shows, fathers do play a unique an d important...
Although the majority of the ten men interviewed have abused alcohol/drugs for longer or shorter periods, it should be noted that some have not, or that their use of alcohol has been at a normal and socially acceptable level. There are other men in our study who also display the tendency...