Mark the letter A, B, C or D on your answer sheet to indicate the correct answer to each of the following questions.
By 1820, there were over sixty steamboats on the Mississippi river, _______ were quite luxurious.
A. which of many
B. many of them
C. many of which
D. many of that
Đáp án: C Mệnh đề quan hệ: steamboats-> which. Dịch: vào năm 1820, có hơn 60 tàu hơi nước trên song Mississippi, rất nhiều trong chúng rất xa hoa