如图:△ABC中,DE∥BC,AD=5,BD=10,AE=3.则AC的值为( )
A:9
B:6
C:3
D:4
— Can you tell me ________? — His home is quite far from the office, I think.
若M⊆{a1,a2,a3,a4,a5},且M∩{a1,a2,a3}={a1,a2},则满足上述要求的集合M的个数是( )