Xiamen Xiang'an Tunnel, _____ is the first undersea tunnel built in mainland China, opened to traffic on April 26th.
A.that B.what C.where D.which
Xiamen Xiang'an Tunnel, _____ is the first undersea tunnel built in mainland China, opened to traffic on April 26th.
A.that B.what C.where D.which
D
略