影响问题解决的主观因素有哪些

Even though Sara had practiced her speech repeatedly, she _____ her conclusion at the talk show. [ ]

A. forgets

B. has forgoten

C. forgot

D. had forgotten

有以下程序 #include main(){char p[20]={′a′,′b′,′c′,′d′},q[]="abc",r[]="abcde"；strcat(P,r)；strcpy(P+strlen(q),q)；printf("％d＼n",strlen(P))；}程序运行后的输出结果是【 】。

A．9

B．6

C．11

D．7

有一种试剂可以一次性区别Ba(NO₃)₂、AgNO₃、K₂CO₃三种物质的溶液，它是[ ]

A．盐酸

B．硝酸

C．硝酸钠

D．氢氧化钠溶液

钢管弯曲时，既受弯矩作用，还受扭矩的作用。( )

狭义的素质