![](https://cos-cdn.shuashuati.com/pipixue-wap/2020-1230-1107-56/ti_inject-812ce.png)
设有如下说明,其中 M A XN 为一足够大的常数: char s1[M A XN]= “”, s2[M A XN]= “ ”, s3[M A XN]= “ Today is ”; char s4[M A XN]= “ 30 July , 2000 ”; char *p ; int I ; (1)Strlen ( s1 ) = ( ); strlen ( s2 ) = ( )。 A . 0 B . 1 C . 2 D . 3 ( 2) Strcat ( s3 , s4 ) = ( )。 A . “ Today is 30 July , 2000 ” B . “ 30 July , 2000 ” C . “ Today is ” D . “ Today is30 July , 2000 ” ( 3) Strcpy ( s3,s4 ) = ( )。 A . “ Today is 30 July , 2000 ” B . “ 30 July , 2000 ” C . “ Today is ” D . “ Today is30 July , 2000 ” ( 4) Strcmp(s3,s4) =( ) 。 A . 0 B . 小于 0 C . 大于 0 D . 不确定 ( 5) Strchr(s3 , “ ” ) 的返回值是( )。 A . 5 B . 6 C . 8 D . 9