A. example
B. excuse
C. expert
D. express

A．why the umbrella was so popular in Europe
B．when and how the umbrella was invented
C．the history and the use of umbrella
D．the development of the umbrella

A．let them shoot over you without any danger
B．be certain of hitting your target(靶子)
C．easily shoot from behind them
D．fire straight at your enemy