Question

quiz: dinosaur extinction in general, the numbers of dinosaurs were beginning to decline about 12 million years before the extinction of non-avian dinosaurs. in addition, dinosaurs in were beginning to decline in biodiversity.

Explanation:

To answer this question, we need to recall knowledge about dinosaur extinction trends.

First Drop - down (Adjective for Dinosaur Numbers):

The first blank likely refers to the type of dinosaurs whose numbers were declining. The appropriate term here is "many" or a similar quantifier - related term, but more accurately, based on paleontological knowledge, the numbers of "large" or "various" but more precisely, the first drop - down is likely "many" (or a similar term indicating a significant portion) and the second is "species" (as we talk about the number of dinosaur species). Wait, actually, the correct fill - ins (based on dinosaur extinction research):

1. The first drop - down: "many" (or a term like "various")
2. The second drop - down: "species"
3. The third drop - down: "certain groups" (or more precisely, based on scientific findings, dinosaurs in "certain ecosystems" or "specific groups" but the most accurate in the context of biodiversity decline is that dinosaurs in "certain lineages" or "specific groups" were declining. However, the standard answer for such a quiz (based on typical educational content about dinosaur extinction) is:

First drop - down: "many"
Second drop - down: "species"
Third drop - down: "certain groups"

But let's correct this with more accurate paleontological context. The numbers of "non - avian" (but no, the sentence is about before non - avian extinction) - actually, the correct answers (from typical educational materials on dinosaur extinction) are:

In general, the numbers of \(\boldsymbol{\text{many}}\) \(\boldsymbol{\text{species}}\) of dinosaurs were beginning to decline about 12 million years before the extinction of non - avian dinosaurs. In addition, dinosaurs in \(\boldsymbol{\text{certain groups}}\) were beginning to decline in biodiversity.

Answer:

First drop - down: many
Second drop - down: species
Third drop - down: certain groups