Question

The idea of fish being able to produce electricity strong enough to light a lamp is almost unbelievable, _____ several kinds of fish are really able to do this.

A．therefore

B．and

C．then

D．but

Answer 1

D

连词辨析。　　A.因此 B.和，并且 C.那么，然后；D.但是。句意：鱼能够产生的电流足够点亮一盏灯的想法，是令人难以置信的，但是有几种与确实能够做到这一点。故选D。