1.C【解析】小球振动的固有周期T=4s,则其固有频率为f=T=0,25Hz,A错误：小球做受迫振动时周期等于驱动力的周期，即等于圆盘转动周期，不一定等于小球的固有周期4s...

1.A【解析】框架在外力F的作用下以速度v水向右2√3做匀速运动，则框架切割磁感线的有效长度L)t,3结合E=BLw可知，电动势E=2W33Bu2t,则E与t成正比，A正确，B错误；...

1.A细节理解题。根据第一段中的Their shapes andcolors stand out against the surrounding landscapes.Consequently,they makefor somefantastic photoopportun...

1.C细节理解题。根据Gotobed中的People were proudthat they could afford to have a bed,thus adding it totheir name.可知，姓氏Gotobed可以表明一个家庭的财...

1.C细节理解题。根据Fees:$l0 per poem.可知，每首诗的参赛费用为10美元，所以参赛者要支付费用。2.D细节理解题。根据IMPORTANT:☆Only onepoem per person,per f...

3.B【解析】“升到不能再升、压缩到不能再压缩、深入到不能再深入”对应图甲、乙、丙共同特征，即两物体达到共同的速度0，系统在水方向动量守恒，有mw0=(m十M),解...

1.C细节理解题。根据第二段中Although courses arenon-credit and do not have letter grades,you need toattend the class in its entirety.可知，参加这门课程...

小1.D细节理解题。根据第二段中There,he found acontinent ecologically rich...and that sustainability hadbeen left out.可知，在Nzamujo看来，可持续性是被...