熔灰 be difficult of: 难于, 不易be difficult to: 很难去……difficult: adj. 1.困难的,(工作等)艰难的。 2.执拗的,顽固的。 a difficult disposition 执拗的性情。 difficult of access 难接近。 difficult to answer 难答。 it’s not difficult: 不难that’s difficult: 那很困难下载手机词典可随时随地查词查翻译