40.

Answer and Explanation

Your Answer is

Correct Answer is J

Explanation

According to the sentence meaning "These bats transmit high-frequency sounds and use echoes to locate their prey", so it is judged that send out and use are the two predicates of the sentence, so item J is correct.

F/G/H item: Doing and to do are non-predicate verbs and cannot be used as predicate verbs, so F/G/H is wrong.