We are busy in preparing for the performance in order not to________ in front of our classmates.
A:lose hope
B:lose face
C:lose confidence
D:lose heart
如图,抛物线y1=﹣x2+4x和直线y2=2x,当y1<y2时,x的取值范围是( )
四年级三个班到工具房领扫把,四年(1)班领走全部扫把的一半少7把,四年(2)班和四年(3)班各领走剩下扫把的一半.最后发现三个班级领的扫把同样多,四年(1)班领了____ 把扫把.