[1a] I think there is left-over food is going.
[1b] I think the left-over food is going bad.
[2a] Why do many people go poor instead of being advanced country? <I don't know what [2a] means>
 Keep your hands up, and go like this till you reach home.
[4a] Turn on the switch, press the button and now we ready to go.
[4b] Turn on the switch, press the button and now we are ready to go.