discourage
1.discourage（劝阻）的宾语后面接from和动名词，不接不定式，如His advice discouraged her from trying again里的from trying不可改用to try。把from改作against也可以，但不及用from普通。
2.discourage是“阻止成功”，“阻止”而不成功便不是discourage，如不可说His advice discouraged her from trying again, but she made two attempts more，该把discouraged改作was meant to discourage。
