实对称矩阵和对角矩阵既相似又合同
A. 对
B. 错
The book________ by Jennifer by the end of last month.
A. have finished
B. finished
C. have been finished
D. had been finished
A stylish bike was bought ________ me by my parents as a birthday present.A. to B. for C. by D. on
A. to
B. for
C. by
D. on
A stranger ________ walk into the building.
A. has seen to
B. was seen to
C. has seen
D. was seen
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