Choose the correct options

1. Tim was very exhausted. He tried
   [to keep|keeping]

   his eyes open, but he couldn't.

2. James needed to borrow some money. He tried
   [to ask|asking]
   his best friend, but he was short of money, too.

3. Kids tried
   [to put|putting]
   the fire out but didn't succeed. Finally, someone called the fire brigade.

4. Kate rang the doorbell, but nobody answered. Then she tried
   [to knock|knocking]
   on the door, but there was still nothing.

5. A baby tried
   [to reach|reaching]
   the toy on the table, but he wasn't tall enough.

6. Could you leave my room for some time? I'm trying
   [to concentrate|concentrating].