Which one of the following behaves both as a nucleophile and an electrophile ?

Which of the following behave both as a nucleophile and an electrophile?

Which of the following species behave both as a nucleophile and an electrophile? (i) CH_(3)C=N: , (ii) CH_(4) (iii) H_(2)C=O , (iv) H_(2)

Which of the following behave both as nucleophile as well as an electrophile ?

Which of the following molecules can act as a nucleophile and an electrophile?