TOEFL Reading: ETS-TOEFL阅读机经 - 9XUUIQEW5LAHB6Z5L$

According to paragraph 4, which of the following is true about possible life on other planets A. It cannot be based on silicon or nitrogen. B. It could not survive on Earth. C. It probably would not be made of elements produced by stars. D. It is likely to have carbon as its chemical basis.