SCIENTISTS HAVE DONE RESEARCHES ON ________ ACTIVIRIES OF THE WORL...

69. - ON TAP HK II TRAC NGHIEM LOP 11
ON TAP HK II TRAC NGHIEM LOP 11

69.

Scientists have done researches on ________ activiries of the world’s volcanoes.

A. sport

B. ecological

C. geothermal

D. geodetic