根据《药品管理法》,以下哪类药品的标签及说明书是不需要印有规定的标志（ ）
A. 外用药品
B. 非处方药
C. 精神药品
D. 含麻黄碱复方制剂
查看答案
8051 single chip microcomputer has () interrupt source
A. 4
B. 5
C. 6
D. 7
The following statement is wrong.
A. Interrupt requests at the same level respond in chronological order
B. Multiple interrupt requests of the same level at the same time will block and the system cannot respond
C. Low priority interrupt request cannot interrupt high priority interrupt request, but high priority interrupt request can interrupt low priority interrupt request
D. Sibling interrupts cannot be nested
In the interrupt request source of AT89S51, it is necessary to add a circuit to realize the interrupt cancellation.
A. Level mode external interrupt request
B. External interrupt request in edge hopping mode
C. External serial interrupt
D. Timing interrupt
After interrupt query confirmation, in the following AT89S51 single-chip microcomputer operation, can immediately respond to is.
A. High priority interrupt processing is currently in progress
B. RETI instruction is currently executing
C. The current instruction is MOV A, R3
D. The current instruction is div instruction and is in the machine cycle of fetching instruction
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