1. 恐怕,害怕,担忧：be active in积极于 | be afraid of恐怕,害怕,担忧 | be alive to发觉,感觉,对......敏感

2. 害怕：9. afford 钱for sth. 买得起某物 | 10. be afraid of 害怕 | 11. after all毕竟

3. 担心发生：afraid adj. 害怕的;担心的 | be afraid of 担心发生... | Africa n. 非洲

4. (名词)v-ing害怕,恐怕：96. be afraid 害怕的,恐惧的 | 97. be afraid of + (名词)v-ing害怕,恐怕.. | 98. be afraid that 认为......,恐怕,担心