The little girl was afraid _____ on the wooden bridge, for she is afraid _____ into the river.
A.to walk, of falling B.to walk, to fall C.of walking, of falling D.of walking, to fall
答：选A解析：该题考查的是be afraid to与be afraid of的用法区别。
在解答该题之前，让我们先来了解一下它们的用法与区别：
be afraid to do 不敢，胆怯去做某事，是主观上的原因不去做，动作受主语控制；
be afraid of doing 担心出现doing的状况、结果。 doing 是客观上造成的，动作往往不受主语控制，意为“生怕，担心”。
例如：She was afraid to step further in grass
because she was afraid of being bitten by a snake.她
生怕被蛇咬着，而不敢在草丛中再走一步。
注:当动作是主语能控制的，两者可以换用。下面
两句用be afraid to do，和be afraid of doing都可以。
She was afraid to wake her husband.她不敢去叫醒她丈夫。(更强调不敢做)
She was afraid of waking her husband.她生怕吵醒她丈夫。(更强调担心)
而此题的句意为“这个小女孩儿不敢在木桥上走，因为她生怕掉进河里。”由此可知，正确答案为A项。
