Electrons in a cathode ray tube have been emitted with a velocity of 1000 m s$^{-1}$. The number of following statements which is/are $\underline {\mathrm{true}}$ about the emitted radiation is ____________.

Given : $\mathrm{h=6\times10^{-34}~J~s,m_e=9\times10^{-31}~kg}$.

(A) The de-Broglie wavelength of the electron emitted is 666.67 nm.

(B) The characteristic of electrons emitted depend upon the material of the electrodes of the cathode ray tube.

(C) The cathode rays start from cathode and move towards anode.

(D) The nature of the emitted electrons depends on the nature of the gas present in cathode ray tube.