单词拼写(共10小题；每小题1分，满分10分）
56. His long illness and ___________(由此引起的)absence put him far behind in his work.
57.You must try to _______________（集中）your mind on work and study
58. The boys _______________（打算、尝试）to leave for camping but were stopped by their parents.
59. He spends all his spare time in collecting stamps and we all say that he is a___________ to collecting stamps.
60.People can easily become ______________(智力上) addicted to drugs when they start taking them.
61.To our sorrow, many children have to __________ (停止)school because of the lack of money. .
62. She hopes to get a job on the local newspaper and ______________(最后) work for the Times.
63. He t_____________ the speech from Spanish into English.
64. The company’s head office is in the city, but it has b________ all over the country.
65. John was touched by the w_____________ of their welcome.
，轨道间接有电动势为E（内阻不计）的电源，现将一根质量为m、电阻为R的金属杆ab水平且与轨道垂直放置在轨道上，金属杆与轨道接触摩擦和电阻均不计，整个装置处在匀强磁场(磁场垂直于金属棒)中且ab杆静止在轨道上，求：