A, B: If the synchronous satellite is at any point outside the equatorial plane, assuming it is "synchronous", then the plane of its orbit is not on the same plane as the gravity of the earth, which is impossible. Therefore, the orbit of the synchronous satellite can only be located in the circular orbit on the equatorial plane of the earth, so the "Xinnuo II" satellite can't be fixed over Xichang and Beijing, so AB is wrong.

C, according to the centripetal force provided by gravity, list the equation: GMmr2=mv2r: v = GMR.

When R takes the minimum value, that is, r=R, v=GMR is the first cosmic velocity, the orbital velocity of the near-earth satellite and the orbital velocity of the maximum circular motion.

The orbital radius of synchronous satellites is larger than that of near-earth satellites. According to the expression of V, we can find that the linear velocity of synchronous satellite must be less than the first cosmic velocity, so C is wrong.

D. Geosynchronous satellites, also known as geostationary satellites, are artificial satellites running in geosynchronous orbit. The running direction of the satellite is the same as that of the earth's rotation. The running orbit is a circular orbit on the equatorial plane of the earth, and its running period is equal to the time of the earth's rotation. Its running angular velocity is equal to that of the earth's rotation, and it always remains stationary relative to the ground. Therefore, d is correct.

So choose D.