1, please write the following program fragment flag government after each instruction execution logic operation, SF, and PF:

MOV AL, 4 ch

AND AL, 0 f0h

The OR BL, 4 ch

XOR AL, AL
MOV AL, 4 ch; ZF is changeless, SF, unchanged, unchanged PF
AND AL, 0 f0h; ZF=0, SF,=0, PF=0
The OR BL, 4 ch; ZF=0, SF,=0, PF=0//this sentence what mean? How to drill the BL?
XOR AL, AL; ZF=1, SF,=0, PF=1?
2, MOV DL, 37 h
MOV AL, 85 h
The ADD AL, DL
DAA
AL=22 h, BL=37 h, CF=1?//... Here is how to drill out the BL again?
The BL here come from?
3, read the following instruction sequence of each item in the space behind the fill in the instruction sequence execution result
MOV DX, 1 f45h
On STC
CX, MOV 95
XOR CH, 0 FFH
SBB DX, CX
DX=1 fb0h, CF=1//how to do?
4, segment that is known as follows,
CX, CMP BX
JNC L1
JNC L2
JMP L3
Hypothesis has the following three groups of CX, BX value, so after the program execution, respectively, to where?
(1) (CX)=D301H, (BX)=D301H
A: to L1
(2) (CX)=2 e50h, h (BX)=8301
Answer: after turning L2//before, is not should not perform JNC, sequentially to JMP?
(3) (CX)=477 bh, (BX)=10 DCH
A: to L1
Shouldn't the CMP A, B
LNC LOOP as long as A greater than or equal to B jump to LOOP, or order