disease and early deaths from all causes.

　　解析：that/which　分析句子结构可知，空处引导定语从句，在定语从句中作主语，修饰先行词study，故填that/which。

　　2．(2018·全国卷Ⅱ)The Chinese Ministry of Agriculture finds that between 2005 - when the government started a soil­testing program________ gives specific fertilizer recommendations to farmers - and 2011, fertilizer use dropped by 7.7 million tons.

　　解析：that/which　空处引导定语从句，并在从句中作主语，修饰"a soil­testing program"，先行词表示物，故用that或者which。

　　3．(2018·浙江高考)Many westerners ________ come to China cook much less than in their own countries once they realize how cheap it can be to eat out.

　　解析：who/that　先行词是Many westerners，指人，故用who/that 引导定语从句，并在从句中作主语。

　　4．(2017·全国卷Ⅲ)But Sarah, ________ has taken part in shows along with top models, wants to prove that she has brains as well as beauty.

　　解析：who　分析句子结构可知，空处引导非限制性定语从句，先行词是Sarah，且空格处在从句中作主语，故用关系代词who。

　　5．(2015·全国卷Ⅰ)I'd skipped nearby Guilin, a dream place for tourists seeking the limestone mountain tops and dark waters of the Li River ________ are pictured by artists in so many Chinese paintings.

　　解析：that/which　根据语境和句子结构可知，空处引导定语从句，先行词指物，关系词在从句中作主语，因此答案为that/which。

　　Ⅱ.单句改错

　　1．(2017·全国卷Ⅱ)In their spare time, they are interested in planting vegetables in their garden, that is on the rooftop of their house.________________

　　解析：that→which　此句是非限制性定语从句，应用which而不能用that引导。

　　2．(2017·全国卷Ⅲ)Around me in the picture are the things they were very important in my life at that time: car magazines and musical instruments.________________

解析：they→that/which　分析句子结构可知，things作其后定语从句的先行词，并在从句中作主语，故关系代词用that或which。