TOEFL Reading: ETS-TOEFL阅读机经 - 43INVU9I5ST33GQGL$

According to paragraph 1, which of the following is true of male songbirds in the first year of life A. They do not begin singing until sometime in late summer or autumn. B. They begin singing earlier in the tropics than in northern latitudes. C. They listen to songs of adults for an extended period of time before they themselves sing. D. Their earliest songs contain the characteristic order of syllables for their species.