一个三角形的一边长是（x+3）cm，这边上的高是5cm，它的面积不大于20cm2，则[ ]
A．x＞5
B．﹣3＜x≤5
C．x≥﹣3
D．x≤5
答案：B
在肋间肌和膈肌的作用下，胸腔会变大、变小．当我们吸气时，胸腔变______，气体进入肺部；当我们呼气时，胸腔变______，气体从肺部排出．
(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（1）处填（）
A.PDM
B.CPM
C.PERT
D.AOA
