People attend a young scientist and technology exhibition in Dublin, Ireland, Jan. 8, 2020. BT Young Scientist and Technology Exhibition 2020, a four-day science and technology competition for Irish secondary school students, opened here on Wednesday. (Photos: Xinhua)

Irish Prime Minister Leo Varadkar addresses the opening ceremony of a young scientist and technology exhibition in Dublin, Ireland, Jan. 8, 2020. BT Young Scientist and Technology Exhibition 2020, a four-day science and technology competition for Irish secondary school students, opened here on Wednesday.

People attend a young scientist and technology exhibition in Dublin, Ireland, Jan. 8, 2020. BT Young Scientist and Technology Exhibition 2020, a four-day science and technology competition for Irish secondary school students, opened here on Wednesday.

Irish Prime Minister Leo Varadkar addresses the opening ceremony of a young scientist and technology exhibition in Dublin, Ireland, Jan. 8, 2020. BT Young Scientist and Technology Exhibition 2020, a four-day science and technology competition for Irish secondary school students, opened here on Wednesday.

A judge (2nd R, Front) talks with contestants at a young scientist and technology exhibition in Dublin, Ireland, Jan. 8, 2020. BT Young Scientist and Technology Exhibition 2020, a four-day science and technology competition for Irish secondary school students, opened here on Wednesday.