1.There are emergency exits in both towers of the hotel, _______ on the other side opposite the elevators.
A.on which are located
B.where is located
C.which locate
D.which are located

2.Loulan City is not at all ______ a traveler who has never seen the desert before can imagine.
A.that B.what C.which D.where

3.Evidence has been piled up ______ specific speech sounds are recognized by babies as young as five months old.
A.what B.which C.that D.if

1 D

先行词为exits（出口），在定语从句中做主语。
locate是及物动词，意思是“使...位/坐落于”，需要用被动语态。

2 B

这是一个表语从句，从句缺少imagine的宾语，所以用what。

3 C

这是一个同位语从句，先行词为evidence。从句的成分皆齐全、语气肯定，所以只能用that。