While the causes of the Cretaceous-Tertiary extinction have received the most attention, Alvarez's paper points out work on the other major mass extinctions that may also be______for the tragedy.

A． martinet : indiscipline
B． sloth : languidness
C． chief : instruction
D． militarist : passion
E． aesthete : equitability

A． van : sedan
B． nebula : star
C． missile : dart
D． toe: foot
E． item : catalogue