String Can'；在MIPS中不能多次写入文件？

我目前正在尝试学习如何写入文件，但是我似乎不能多次写入文件。如何将多个字符串写入一个文件，或者在本例中多次写入同一字符串？谢谢

.data
str_exit: .asciiz "test.txt"
str_data: .asciiz "This is a test!"
str_data_end:

.text

file_open:
    li $v0, 13
    la $a0, str_exit
    li $a1, 1
    li $a2, 0
    syscall  # File descriptor gets returned in $v0
file_write:
    move $a0, $v0  # Syscall 15 requieres file descriptor in $a0
    li $v0, 15
    la $a1, str_data
    la $a2, str_data_end
    la $a3, str_data
    subu $a2, $a2, $a3  # computes the length of the string, this is really a constant
    syscall

    move $a0, $v0  # Syscall 15 requieres file descriptor in $a0
    li $v0, 15
    la $a1, str_data
    la $a2, str_data_end
    la $a3, str_data
    subu $a2, $a2, $a3  # computes the length of the string, this is really a constant
    syscall
file_close:
    li $v0, 16  # $a0 already has the file descriptor
    syscall

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我已经花了半个多小时试图解决这个问题，但在我发布问题的那一刻，我就自己解决了。我将$a0设置为$v0，因为我在第一次系统调用后使用了$v0，这意味着$a0中的值不正确：\