Nhận biết (M1)

Recent sediment analyses of the Scottish Highlands have led some geologists to propose that the currently barren landscapes were once covered by extensive glaciers. This hypothesis _________ that specific glacial formations, such as those attributed to the Younger Dryas period, persisted without interruption throughout the Holocene cannot be upheld, geologists Dr. Alan Smith and Dr. Fiona Kelly argue, unless other contributing factors are systematically eliminated.

Which choice completes the text so that it conforms to the conventions of Standard English?

• A.

  suggests

• B.

  suggested

• C.

  suggesting

• D.

  has suggested