Questions

#include
int main( int count,char * argv[] ) {
    int i;
    FILE *ptr;
    char *str;
    char ch;
    if( count == 1) {

         printf( "The syntax of the command is incorrect.\n" );
    }
    for( i=1;i<cout;i++ ){
         ptr=fopen(argv[i],"r");
         if(ptr==NULL){
             printf("The system cannot find the file specified.");
             if(count>2)
                 printf("\nError occurred while procesing : %s.\n",argv[i]);
         }
         else {
             if(count>2) {
                 printf("%s\n\n",argv[i]);
             }
             while((ch=getc(ptr))!=-1)
                 printf("%c",ch);
         }
         fclose(ptr);
    }
    return 0;
}

Save the above file as open.c, compile and execute the go to command mode (current working directory) and write: open xy.c (xy.c any file present in that directory)
To run the open command in all directories and drive you will have to give the path of current working directory in command mode. Write:
C:tc\bin>PATH c:\tc\bin
Now press enter key. Now your open command will work in all directory and drive.

rotator

The amount of water vapor in the air is called Humidity. The amount of water vapor that air acn hold depends on the temperature of the air. The amount of water vapor in the air as compared with the amount of water that the air could hold is called Relative humidity.

Compound word means when two or more words join together to make a single word that gives a new meaning.

Here in the options, Self-evident is the compound word.

The simplest organic compounds contain only the elements carbon and hydrogen, and are called hydrocarbons.

Here all the given options are hydrocarbons.

Venus is known as earth's twin because of its closeness to the earth with respect to size, mass(weight) and density.