undefined reference to `FMOD_System_Create'

I write a test sample that call fmod api, but it always occur undefined error as below. I am sure i have line to so file in the Android.mk. could you help me?
thanks a lot.

I have another question. before i use native c to write a sample code, and it’s a pure c execute file. I don’t import fmod.jar, then it would occur fmod init failed. It means if i want to write a sample code to play music, it must be a apk file, right?

Error:(33) undefined reference to `FMOD_System_Create’

my sample code download path:https://mega.nz/#!7hQGXJoK!IAwkmi3pQ-L6uS4ExFbdDGn1yaFexZ2geN7MU3Hz23s

The error sounds like your compiler cannot find the FMOD library, therefore cannot find the FMOD_System_Create symbol. I recommend double checking your build setup to ensure the library is being found.

Regarding your second question, yes your application must be a proper APK that includes the fmod.jar or System::init will fail.