________ excited Geoff Marcy most was ________ there were planets in other solar system where life might exist.
A. It; if B. That; whether C. What; whether D. What; that
________ excited Geoff Marcy most was ________ there were planets in other solar system where life might exist.
A. It; if B. That; whether C. What; whether D. What; that
C。句意为：让Geoff Marcy最兴奋的是在其他的恒星系中是否存在有生命生存的行星。what引导主语从句。