求高手解答关于centos挂载不上u盘的问题

我用的是centos 5.9，是个菜鸟，刚刚为了加快开机速度，关了好多个服务，本来u盘插上去在桌面上会自动挂载上，现在怎么也挂载不上了，求各位大虾帮帮忙。
[root@localhost xiaobo]# fdisk -l

Disk /dev/sda: 500.1 GB, 500107862016 bytes
255 heads, 63 sectors/track, 60801 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes

Device Boot Start End Blocks Id System
/dev/sda1 * 1 13 104391 83 Linux
/dev/sda2 14 39176 314576797+ 83 Linux
/dev/sda3 39177 42440 26218080 83 Linux
/dev/sda4 42441 60801 147484732+ 5 Extended
/dev/sda5 42441 45704 26218048+ 83 Linux
/dev/sda6 45705 48968 26218048+ 83 Linux
/dev/sda7 48969 51579 20972826 83 Linux
/dev/sda8 51580 52884 10482381 83 Linux
/dev/sda9 52885 53406 4192933+ 82 Linux swap / Solaris
/dev/sda10 53407 60801 59400306 83 Linux

Disk /dev/sdc: 4026 MB, 4026531840 bytes
255 heads, 63 sectors/track, 489 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes

Device Boot Start End Blocks Id System
/dev/sdc4 * 1 490 3932128+ b W95 FAT32
Partition 4 has different physical/logical endings:
phys=(488, 254, 63) logical=(489, 135, 30)
[root@localhost xiaobo]# mount /dev/sdc /mnt/usb_disk
mount: you must specify the filesystem type