题目内容
The abacus _____ in _____ century by Chinese.
[ ]
A. invented; six
B. was invented; the sixth
C. invented; the sixth
B. was invented; the sixth
C. invented; the sixth
B

练习册系列答案
相关题目
--When _____ the abacus _____? -- In the sixth century by the Chinese people.
A.is, invented | B.did, invent | C.was, invented | D.does, invent |
--When _____ the abacus _____? -- In the sixth century by the Chinese people.
A.is, invented |
B.did, invent |
C.was, invented |
D.does, invent |