1 . World Environment Day is a UN Environment-led global event, ______ takes place on June 5 every year and is celebrated by thousands of communities worldwide. （用适当的词填空）

2 . In this case, cool evening air is a slightly different temperature than the solar cell in the panel. That becomes energy, ________is transformed into electricity.(用适当的词填空)

3 . Climbing, _________ entered the Olympics three years ago in Tokyo, will also be one of the events in the 2024 Paris Olympics. (用适当的词填空)