Which figure of speech is used in the bolded lines in the following excerpt from this poem by langston hughes?

dreams

hold fast to dreams

for if dreams die

life is a broken-winged bird

that cannot fly.

a. metaphor

b. onomatopoeia

c. simile

d. alliteration

tree and the cat in the tree

the krebs cycle and electron transport occur in the mitochondria, though other than that i would need to know more information.

wood chucks can't chuck wood so no wood

research question: do the predicted benefits of genetic enhancements outweigh the possible negative consequences of this technology?  

what information do i need to research in order to answer this question?  

-predicted benefits of genetic enhancements

-negative consequences of genetic enhancements

-existing, if any, consequences of the new technology

-possible consequences if the technology is perfected

what sources will have the information?

-scientific research documents or news articles summarizing research

-articles in science and medical journals, magazines, and electronic databases

-books

-experts at genetics: geneticists, scientists, professors

here you go have a nice day