Some large rocks jutted out of the dust cloud, and Armstrong focused on them during his descent so he could determine the spacecraft's speed.
sˌʌm lˈɑːɹdʒ ɹˈɑːks dʒˈʌɾᵻd ˌaʊɾəv ðə dˈʌst klˈaʊd, ænd ˈɑːɹmstɹɔŋ fˈoʊkəst ˌɔn ðˌɛm dˈʊɹɹɪŋ hɪz dᵻsˈɛnt sˌoʊ hiː kʊd dɪtˈɜːmɪn ðə spˈeɪskɹæfts spˈiːd.