多项选择题

Directions: For the following questions, select the two answer choices that, when used to complete the sentence, fit the meaning of the sentence as a whole and produce completed sentences that are alike in meaning. Because it arrives so early in the season, before many other birds, the robin has been called the ______ of spring.

A. prototype
B. hostage
C. harbinger
D. herald
E. progeny
F. newcomer