Answer:
A. Scientists used a submarine to send a camera under some ice.
Step-by-step explanation:
the rest of these sentences are opinions, facts are always definitively true or false regardless of a personal opinion or perspective
B. Scientists should choose warmer places to do their work.
This is a normative statement about what scientists should do, and is not necessarily true or false.
C. None of the species found in Lake Vostok are important.
Whether or not the species in Lake Vostok are important is subjective and not true or false, as this opinion can differ from person to person.
D. The beauty of Antarctica makes up for its cold temperatures.
This sentence states an opinion on the beauty of Antarctica. Another person might find Antarctica not beautiful at all.
A. Scientists used a submarine to send a camera under some ice.
This statement is presented in an objective style, with used as the key word. Scientists either used or did not use a submarine to send a camera under some ice. This statement remains true or false regardless of different perspectives or opinions. The facts supporting this statement prove it is true because there is definitive evidence that scientists have indeed used a submarine to send a camera under some ice.