Small echo problem.

Solve the small problem of echo-Linux general technology-Linux technology and application information. The following is a detailed description. I want to add a sentence to the.txt text file. "The following is ..., you know... ", then input the file name under the root directory to the.txt text file. The result is incorrect... solve... how can we use echo ??? : 0wl; l1
# Include
Int main ()
{
System ("echo" Below is..., you know... "> a.txt ");
System ("ls/> a.txt ");
}


Error message:
L. c: In function 'main ':
L. c: 4: 2: error: stray '\ 344' in program
L. c: 4: 2: error: stray '\ 273' in program
L. c: 4: 2: error: stray '\ 245' in program
L. c: 4: 2: error: stray '\ 344' in program
L. c: 4: 2: error: stray '\ 270' in program
L. c: 4: 2: error: stray '\ 213' in program
L. c: 4: 2: error: stray '\ 346' in program
L. c: 4: 2: error: stray '\ 230' in program
L. c: 4: 2: error: stray '\ 257' in program
L. c: 4: 26: error: expected identifier before '. 'token
L. c: 4: 26: error: stray '\ 344' in program
L. c: 4: 26: error: stray '\ 275' in program
L. c: 4: 26: error: stray '\ 240' in program
L. c: 4: 26: error: stray '\ 346' in program
L. c: 4: 26: error: stray '\ 207' in program
L. c: 4: 26: error: stray '\ 202' in program
L. c: 4: 26: error: stray '\ 345' in program
L. c: 4: 26: error: stray '\ 276' in program
L. c: 4: 26: error: stray '\ 227' in program