[일단완료]왕초보 질문! Hello World 프로그램 컴파일 에러! 왜?

그 유명한 Hello World 프로그램입니다만
왕초보인 저에게는 너무나 어렵네요.

-소스는 아래와 같구요.
#include QApplication
#include QLabel
-- 참고 : 꺽새는 생략 했습니다. 이건왜 없어지죠?

int main(int argc, char **argv)
{
QApplication app(argc,argv);
QLabel *hello = new QLabel("Hello Qt" "",0);
hello->show();
return app.exec();
}

-컴파일 에러 메세지는 다음과 같습니다. 선배님들의 조언을 부탁드립니다.
dreamer@dreamer-desktop:~/바보$ qmake -project
dreamer@dreamer-desktop:~/바보$ qmake
dreamer@dreamer-desktop:~/바보$ make
g++ -c -pipe -g -Wall -W -O2 -D_REENTRANT -DQT_NO_DEBUG -DQT_THREAD_SUPPORT -DQT_SHARED -DQT_TABLET_SUPPORT -I/usr/share/qt3/mkspecs/default -I. -I. -I/usr/include/qt3 -o hello.o hello.cpp
hello.cpp:1:24: error: QApplication: No such file or directory
hello.cpp:2:18: error: QLabel: No such file or directory
hello.cpp: In function ‘int main(int, char**)’:
hello.cpp:6: error: ‘QApplication’ was not declared in this scope
hello.cpp:6: error: expected ‘;’ before ‘app’
hello.cpp:7: error: ‘QLabel’ was not declared in this scope
hello.cpp:7: error: ‘hello’ was not declared in this scope
hello.cpp:7: error: expected type-specifier before ‘QLabel’
hello.cpp:7: error: expected ‘;’ before ‘QLabel’
hello.cpp:9: error: ‘app’ was not declared in this scope
hello.cpp: At global scope:
hello.cpp:4: warning: unused parameter ‘argc’
hello.cpp:4: warning: unused parameter ‘argv’
make: *** [hello.o] 오류 1