True. Its like when you're think of the word you want to say but you forget what the word is.
The answer for this question would be “but-“
Carbon can form four covalent bonds. Covalent bonds are chemical bonds that form between nonmetals. In a covalent bond, two atoms share a pair of electrons. By forming four covalent bonds, carbon shares four pairs of electrons, thus filling its outer energy level and achieving stability.
The last one is the answer I think