The "white chalk cliffs of Dover" are mentioned in line 14 of the passage to（）
A: show where the plankton sediment first began to build up
B: provide an example of a plankton buildup that scientists cannot explain
C: provide all example of the buildup of plankton sediment
D: indicate the largest single plankton buildup on Earth
A: show where the plankton sediment first began to build up
B: provide an example of a plankton buildup that scientists cannot explain
C: provide all example of the buildup of plankton sediment
D: indicate the largest single plankton buildup on Earth
举一反三
- 海洋生物包括 A: Plankton B: Nekton C: Mammals D: Benthos
- 海洋生物包括 A: Plankton B: Necton C: Mammals D: Benthos
- The white cliffs of Dover are an example of a/an ( ) chalk deposit. A: foraminiferan B: radiolarian C: heliozoan D: difflugian E: arcellian
- We've all paid a ___ bill or purchased gasoline. A: buildup B: contributor C: component D: utility
- The plant "sumpweed" is mentioned in line 25 in order to（） A: contrast a plant with high nutritional value with one with little nutritional value B: explain the medicinal use of a plant C: clarify which plants grew better in places where trees were not cut down D: provide an example of a plant that was easy to domesticate