Family ______ and conflicts may lead to violence.(1.0)
A. tensions
B. tends
C. trends
D. tenders
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______ is the center of our planetary system was a difficult concept to grasp in the Middle Ages.(1.0)
A. It is the sun and not the earth
Being the sun and not the earth
C. The sun and not the earth
D. That the sun and not the earth
______ has been a topic of continual geological research.(1.0)
A. Did the continents originate
B. How did the continents originate
C. Have the continents originated
D. How the continents originated
-Doesn’t Helen live on this street? -No. This is ______ Leon lives.(1.0)
A. which
B. where
C. that
D. what
I doubt ______.(1.0)
A. whether he can come
B. if he can come or not
C. while he will be here
D. what will he do
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