Choose the correct verb form in the following sentences

I wanted to go on my own but he insisted ... coming too.
1. to
2. on
3. 0
4. at
Don't try and do too many things at the same time. Concentrate ... doing one at a time.
1. at
2. on
3. in
4. about
Ellen is a doctor. She specialises ... alternative medicines.
1. in
2. to
3. on
4. at
As we were sailing away, another boat crashed ... us.
1. on
2. at
3. into
4. in
I prefer orange juice ... grapefruit juice.
1. than
2. at
3. on
4. to
I hope you succeed ... finding the job you want.
1. on
2. to
3. in
4. at
Whatever happened ... Jim Lennon? I don't hear about him anymore.
1. at
2. 0
3. on
4. to
This country is divided ... several regions.
1. in
2. to
3. on
4. into
Ed decided to give up studying to concentrate ... being a musician.
1. at
2. on
3. 0
4. in
I felt filled ... happiness to see her again.
1. with
2. up
3. in
4. of