I found that there are only host objects and network objects in PIX. Therefore, if I have ten machines such as 10.1.0.1, 10.1.0.3, 10.1.0.5,...... 10.1.0.19 and each of them needs to access 100 subnets such as 10.0.1.0/24, 10.0.3.0/24, 10.0.5.0/24, ...