Read the following passage and mark the letter A, B, C, or D on your answer sheet to indicate the correct answer for each of the blanks from 28 to Question 50. Fill in the appropriate word in question 30
In the late 1930s, a group of leading American scientists seeking dinosaur fossils made some noteworthy (28) ___________. Although one of their expeditions discovered no fossils, it proved nonetheless historic expedition, which took place along the banks of the Paluxy river in Texas, something extraordinary was revealed: a dinosaur track, clearly distinguishable in the rock. These dinosaur footprints (29) ___________ their preservation to the salts and mud that covered them and then hardened into rock, before coming to light 100 million years later. Tracks like these are (30) ___________ to experts. There have been great gaps in scientists’ understanding of dinosaur behavior, and so such footprints are useful since they provide direct evidence of how dinosaurs actually moved. Scientists have used these and (31) ___________ footprints to determine how quickly different species walked, concluding that many kinds of dinosaur must have travelled in (32) ___________.
A. costly
B. rare
C. invaluable
D. unique
Answer C
Kỹ năng: Đọc
Giải thích:
A. costly: có giá trị
B. rare: hiếm, ít
C. invaluable: vô giá, cực kì hữu dụng; valuable to/ for sb/sth(cụm từ cố định)
D. unique: độc nhất
Nghĩa của câu là: Những dấu vết này rất hữu ích cho các chuyên gia.
=> vậy đáp án câu này là: C. invaluable