D because they were now aware of challenges that may arise like disease when invading
This is false. Subsistence farming is <em>only</em> <em />for ones single use, and not for trade.
I hope this helps you! Good luck :)
Answer:
The use of the abacus was expanded and refined.
Explanation:
The abacus was invented during the Yuan Dynasty which lasted between 1206AD till 1368AD and then it was expanded and refined by the Ming Dynasty (1368AD-1644AD).
There have been archaeological proof of this as the writings of Tao Zongyi describes in his book that the new servants, unlike the older and more experienced ones were "just like abacus heads" and that they would not move unless they were made to move. This bears credence to the fact that the abacus was already widely used then.
An abacus was used to count numbers.
Not only must the technology be made available, but teachers must alos be ... again used the State of the Union to address the issue of technology in the classroom, hope this helps
D, gives an opinion of the case.
