[問題]考古題 form26-11

[jasminelcj]

Geologists believe that the Bering land bridge, over which human beings are thought to have first entered the Americas, disappered about 14,000 years ago when massive glaciers melted ang caused the sea level to rise several hundred feet worldwide.

(A)are thought to have first entered
(B)were thought first to enter
(C)are thought at first to enter
(D)are thought of as first entering
(E)were thought to first enter

ans:A
請問各位大大 這題該如何做? 我覺得應該是過去式
麻煩各位幫我解惑一下 感激不盡

[sandarac]

Geologists believe that the Bering land bridge, over which human beings are thought to have first entered the Americas, disappered about 14,000 years ago when massive glaciers melted ang caused the sea level to rise several hundred feet worldwide.

(A)are thought to have first entered
(B)were thought first to enter
(C)are thought at first to enter
(D)are thought of as first entering
(E)were thought to first enter

ans:A
請問各位大大 這題該如何做? 我覺得應該是過去式
麻煩各位幫我解惑一下 感激不盡

If Geologists still think these "human beings" to have first entered the Americas, you should use the present tense---"are"!

If they no longer think so, you should use the past tense!