问题

To meet the need of the London Olympic Gamesin 2012,many new stadiums are reported to________ in Britain.
A:held;beconstructed
B:to be held;have constructed
C:to be held;bebeing constructed
D:to be held;be constructing
B:to be held;have constructed
C:to be held;bebeing constructed
D:to be held;be constructing
正确答案是: