ip route

RouterOS Beginner Basics
1

i have routerboard 750gl
2dsl lines , 1lan
i have question about one thing

0 A S 0.0.0.0/0 192.168.1.1
1 A S 0.0.0.0/0 192.168.0.1
2 A S 0.0.0.0/0 192.168.0.1
3 S 0.0.0.0/0 192.168.1.1
4 ADC 10.0.0.0/24 10.0.0.2 lan
5 ADC 192.168.0.0/24 192.168.0.2 wan2
6 ADC 192.168.1.0/24 192.168.1.2 wan1

at number 3 why its only static s

2

Route 3 is only “S” because it is static and not active.

Form information on the meaning of the letters see this post:
http://wiki.mikrotik.com/wiki/Manual:IP/Route#Route_flags

You may want to remove your existing default routes and add one like this:
/ip route add dst-address=0.0.0.0/0 gateway=192.168.1.1,192.168.0.1 check-gateway=ping

If you want more info on equal cost mult-path routing (ie two DSL lines) then look at this:
http://wiki.mikrotik.com/wiki/ECMP_load_balancing_with_masquerade