教师的言传身教对学生的学习、品行的发展起着重要的作用，着体现教师的职业角色的哪一方面（）。
参考答案：行为示范者
碎屑颗粒的圆度只有棱角状和圆状两个级别。
(1) is a method of constructing a project schedule network diagram that uses boxes or rectangles, referred to as nodes, to represent activities and connects them with arrows that show the dependencies.This method includes following types of dependencies or precedence relationships: (2) the initiation of the successor activity, depends upon the completion ofthe predecessor activity.(3) the initiation ofthe successor activity, depends upon the initiation ofthe predecessor activity.
空白（3）处填（）
A.F-S
B.F-F
C.S-F
D.S-S
