How many planets orbiting other stars have the two scientists discovered so far

A．The planet is not as protective as Jupiter.
B．The planet is close to star 55 Cancri.
C．The planet proves to be a gas planet.
D．The planet is as large as Jupiter.

A．why English has become a global language
B．how many people in the world speak English
C．how people in the world learn English as a foreign language
D．whether we need to worry about English being a world language