question: ocean:waves:surfboard
choices.label: A B C D
choices.text: pool:spray:diving vascular:blood:cell forest:tree:bird sky:airflow:hot air balloon
explanation: there are "waves" in the "ocean", and the power source of the "surfboard" is the "waves". there is "spray" in the "pool", but the power source of "diving" is not "spray". "blood" is in the "vascular", but the power source of a "cell" is not "blood". the "trees" are in the "forest", but the power source of the "bird" is not the "trees". the "airflow" is in the "sky", and the power source of the "hot air balloon" is the "airflow".
relation: ocean waves R3.6
relation: waves surfboard R5.4
relation: pool spray R3.6
relation: vascular blood R3.6
relation: forest tree R3.6
relation: sky airflow R3.6
relation: airflow hot air balloon R5.4