某介子的固有寿命为s,速度为0.6c的该介子的寿命是( )s。 A.
B.
C.
D.

A．It is a good experience to live in American families to learn English.
B．It can be a good experience so they can get a different angle of education.
C．It is a good experience to study in an English-speaking country.

A．
B．
C．
D．