结构为动词+不定式 例如：
afford aim agree arrange ask decide
bother care choose demand desire determine
elect endeavor hope ail help learn
long 渴望 mean manage offer plan pretend
refuse tend undertake expect hate intend
例如：
The driver failed to see the other car in time.
司机没能及时看见另一辆车。
He offered to help me.
他表示愿意帮助我。
