[解析]
(1)D.细节理解题:从第一段的句子:tomato is a kind of very delicious vegetable.可知西红柿是一种可口的蔬菜,选D
(2)B.推理判断题.根据文章第一段But in the 18th century,Americans never ate tomatoes.They grow them in their gardens because tomato plants are so pretty可知在18世纪的时候,美国人还不吃西红柿,最快也就是在19世纪美国人才开始吃西红柿.故B正确.
(3)A.细节理解题.根据文章第二段第2行He had been to Paris,where he learned to love the taste of tomatoes.可知Jefferson 是在巴黎的时候知道西红柿好吃的,选A.
(4)C.细节理解题.根据They never thought their president would serve his honored guests poison apples.their president他们自己的总统,当然客人是本国的.故选C.
(5)A.细节理解题.根据The President taught his cook a way for a cream of tomato soup.The guests thought the soup tasted really good.可知这句B符合文意根据The guests thought the soup tasted really good.可知C这句符合文意;根据They never thought their president would serve his honored guests poison apples.可知D这句符合文意,根据第二段The guests thought the soup tasted really good.They never thought their president would serve his honored guests poison apples可知并不是所有的客人都知道主席聚会上的汤是用西红柿做的;故选A.