cannot check and run playbook.yml , error reporting

[mukulmatta]

[root@testvm1 cis-rhel-ansible]# ansible-playbook -i hosts -C playbook.yml
ERROR! A playbook must be a list of plays, got a <class 'ansible.parsing.yaml.objects.AnsibleMapping'> instead

The error appears to be in '/etc/ansible/cis-rhel-ansible/playbook.yml': line 18, column 3, but may
be elsewhere in the file depending on the exact syntax problem.

The offending line appears to be:

hosts: all
^ here

---

[root@testvm1 cis-rhel-ansible]# ansible-playbook playbook.yml -i hosts --list-tags
ERROR! 'accelerate' is not a valid attribute for a Play

The error appears to be in '/etc/ansible/cis-rhel-ansible/playbook.yml': line 18, column 3, but may
be elsewhere in the file depending on the exact syntax problem.

The offending line appears to be:

• hosts: all
  ^ here

[jfucanada]

Got same errors.