Can i site a source once in a paragraph if it is used multiple time mla

Read the excerpt from the strange case of dr. jekyll and mr. hyde. from that time forward, mr. utterson began to haunt the door in the by-street of shops. in the morning before office hours, at noon when business was plenty, and time scarce, at night under the face of the fogged city moon, by all lights and at all hours of solitude or concourse, the lawyer was to be found on his chosen post. "if he be mr. hyde,” he had thought, "i shall be mr. seek.” how is mr. utterson characterized in the excerpt? as mysterious as depressed as determined as generous

Ineed quick me on this one and others

Write about a scientist and present information including a short biography, contribution,their scientific achievements and contribution to science