题目内容

事务T0、T1和T2并发访问数据项A、B和C，下列属于冲突操作的是______。

A. T0中的read(A)和T0中的write(A)
B. T0中的read(B)和T2中的read(C)
C. T0中的write(A)和T2中的write(C)
D. T1中的read(C)和T2中的write(C)

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数据库管理系统采用三级加锁协议来防止并发操作可能导致的数据错误。在三级加锁协议中，一级加锁协议能够解决的问题是______。

A. 丢失修改
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