S1="good",S2="morning",执行串连接函数ConcatStr(S1,S2)后的结果为()。
A. "goodmorning"
B. "good morning"
C. "GOODMORNING"
D. "GOOD MORNING"
设串S1="ABCDEFG",S2="PQRST" ,则ConcatStr(SubStr(S1,2,LenStr(S2)),SubStr(S1,LenStr(S2),2))的结果串为()。
A. BCDEF
BCDEFG
C. BCPQRST
D. BCDEFEF