【推荐1】Thanksgiving is a popular American holiday, __________ is celebrated on the fourth Thursday in November every year.(用适当的词填空)

【推荐2】The expert designed a solution____________ could prevent soil loss by planting trees in the desert.(用适当的词填空)

【推荐3】We came to a place ___________ they had never paid a visit before.
(in which / to which / on which)

【推荐1】Mary passed the important test, ________ made her parents very happy. (用适当的词填空)

【推荐3】When it comes to the majority of the latest technologies in the next 20 years, none has greater potential than the technology being developed in these young people’s company,________in my eyes will lead to a revolution. (用适当的关系词填空)