若复数z=1+ai(i是虚数单位)的模不大于2,则实数a的取值范围是 .
--- Mom, I’ m going to the graduation dance tonight but I don’t think I look attractive enough.
--- Oh, darling, don’ t worry. _______.
A.They don’t know what beauty is
B.Nobody will care about it
C.You look perfect the way you are
D.Impossible is nothing
规范教育学的形成以德国赫尔巴特的代表作( )的出版为标志。
A.《大教学论》B.《民主主义与教育》C.《普通教育学》D.《高等教育学》