教学中学生要掌握直接经验和间接经验，重点掌握（ ）。

A．直接经验

B．间接经验

C．直接经验与间接经验并重

D．先掌握直接经验，后掌握间接经验

My goodness, how lucky we are! If there had been p1aces for us on the aero plane, we _______ dead

now. [ ]

A. will be

B. would be

C. would have been

D. had been