强调学生的积极参与，体现学生的主体地位，给学生留有充分的时间参与活动，这种体育教学是“放养式”教学。
参考答案：错
上颌窦的淋巴引流主要到（）
A.上颈深淋巴结
B.二腹肌后组淋巴结
C.下颌下淋巴结
D.颏下淋巴结
E.上颈深+下颌下+颏下淋巴结
--I'm told that John had another car accident this morning.
--I believe not. He _________so careless.
A．shouldn't have been
B．wouldn't have been
C．couldn't have been
D．mustn't have been
