A.一旦受精,黄体继续发育,分泌孕酮与雌激素
B.2周以后,胎盘的绒毛膜促性腺激素代替垂体的促性腺激素
C.绒毛膜促性腺激素的靶器官是子宫,刺激子宫不断发育,维持妊娠
D.8~10周后,胎盘又分泌孕酮与雌激素
E.雌激素使子宫肌增大,孕酮则使子宫静息,起安胎作用
下列文法中,_______是算符优先文法。
A.G1:S→Aa A→bB B→a
B.G2:S→Aa A→Bb B→a
C.G3:S→aAB A→b B→a
D.G4:S→aSb|a
下面程序的输出是【 】。 main() {enum em{em1=3,em2=l,em3}; char*aa[]={"AA","BB","CC","DD"}; printf("%s%s\n",aa[eml],aa[em2],aa[em3]); }
下面程序的输出是【 】。 main() { enum em{em1=3,em2=1,em3}; char*aa[]={"AA","BB","CC","DD"}; printf("%s%s%s\n",aa[em1],aa[em2],aa[em3]); }
下面程序的输出是【 】 main() {enum em{eml=3,em2=1,em3}; char*aa[]={"AA,"BB","CC","DD"} printf("%s%s%\n",aa[em1],aa[em2],aa[em3]); }
下面程序的输出走【 】。 main() {enum em {em1=3,em2=1,em3}; char*aa[]={"AA","BB","CC","DD"}; printf("%s%s%s\n",aa[em1],aa[em2],aa[em3]); }
下面程序的输出是【 】。 main() {enum em{em1=3,em2=1,em3}; char*aa[]={"AA"m,"BB","CC:,"DD"}; printf("%s%s%s\n,aa[em1],aa[em2],aa[em3]); }
设有语言L(G(S))={a}+{b},下面描述该语言正确的文法是_______。
A.S→AB A→aA|ε B→Bb|b
B.S→AB| AS A→aA|a B→b
C.S→AB| AS A→aA|a B→Bb|ε
D.S→SA| A A→aAb|a