Answer:
Order effects.
Explanation:
Firstly, internal validity will be explained to be the approximate about certain inferences regarding cause relationship and also cause-effects.
In the other hand, order effect which mainly known to be testing effects is seen to only occur in experimental research and also in quasi-experimental research designs that have more than one stage. Furthermore, research designs of this form is seen to involve a pre-test and also a post-test. Circumstances of this kind pulls the fact that the person taking part in the research is tested more than once can influence their scores in the post-test, therefore confounding the results.
It was Portugal that started discovering new lands and creating instruments to study the sea.
They took control of Aksum's port city, cutting them off from trade.