[填空题]
A galaxy is moving away wbp7a9 pq)joih 70x6 m5d1wtjmc *fm3 from Ea5buav 4d -qsa5rth. The "blue" hydrogen line at 434 nm emitted from 5uvba 4q sda5-the galaxy is measured on Earth to be 650 nm.
(a) How fast is the galaxy moving? v $\approx$ c
(b) How far is it from Earth? d $\approx $ $ \times 10^9\ \text{y}$
