已知直线l，m，n，平面α，m⊂α，n⊂α，则“l⊥α”是“l⊥m，且l⊥n”的 ______条件．（填“充分不必要”、“必要不充分”、“充要”、“既不充分也不必要”之一）

People in many countries were sad at the news ______ Samaranch, Lifetime Honorary President of the Olympic Committee, died at 89 on April 21st.

A．which

B．that

C．what

D．when