Most of the time it would be beachhead, but it can also be drop-offs, cliffs, etc
hope this helps
16+5 =21. M is 16 if you do 21-5=16
D.) countries forcefully take territory from neighbors, this should be correct :)
Answer:
The Himalayas in the west and the Gobi in the north were two important geographic barriers. They made the spread of ideas and goods between the ancient Chinese and others outside the region difficult. The early Chinese were so isolated that they came to believe that China was the world's only civilization.
Explanation: