【单选题】Erhu so metimes known i n the W est as the _______ ,is a two-stringed bowed musica l instrumen t a nd i s use d a s a sol o instrumen t a s wel l a s fo r smal l en s emble s an d la r g e or c h e s ...
【单选题】A derivative is a security which 'derives' its value from another underlying (61) instrument, index, or other investment. Derivatives are available based on the performance of stocks, interest rates, ...