“掩耳盗铃”是大家熟悉的成语故事.从物理学角度分析,盗贼所犯的错误是:既没有阻止声音的____ ,又没有阻止声音的____.
函数f(x)=log3x-(12)x-2的零点所在区间为( )
下列哪一组所列的器具都是杠杆( )
—It is so cold today.
—Yeah.You'd better not ______ your coat when you are in the classroom.