ID	Activity	Duration	Predecessors
1	Baseball Stadium
2	Clear stadium site	70 days
3	Demolish building	30 days	2
4	Set up construction site	70 days	3
5	Drive support piling	120 days	2
6	Pour lower concrete bowl	120 days	5
7	Pour main concourse	120 days	3,6
8	Install playing field	90 days	3,6
9	Construct upper steel bowl	120 days	3,6
10	Install seats	140 days	7,9
11	Build luxury boxes	90 days	7,9
12	Install jumbotron	30 days	7,9
13	Stadiuminfrastructure	120 days	7,9
14	Construct steel canopy	75 days	10
15	Light installation	30 days	14
16	build roof supports	90 days	6
17	Construct roof	180 days	16
18	Install roof tracks	90 days	16
19	Install roof tracks	90 days	17,18
20	Inspection	20 days	8,11,13,15,19

draw a network for Shoreline Stadium and determine the critical path for the project. Which activities are critical in this project?