Answer: challenging problems
Explanation:
Whatever completes the text would have be something that relates to the problems that are to be solved as this is the subject of the sentence and it would have to be in the negatives due to the use of the word "unfortunately".
The best option is therefore the above because too many challenging problems relates to the subject of problems and is not a good thing.
Parents have ( or have. Not ) different standards for there son and daughters because...
collaboration, joint action, combined effort, teamwork, partnership, coordination, liaison, association, synergy, synergism, give and take, compromise
Answer:
C
Explanation:
The Greco-Roman physician Galen advocated the bleeding of patients with leeches, a practice that persisted in various parts of the world for many centuries. Throughout most of Western history, leeching—or leechcraft—became such a common practice that a physician was commonly referred to as a “leech.”
The Apollo 13 was the 3rd mission to land the moon. The explosion of the oxygen tank effected this because the crew was forced to orbit the moon and land safely back to Earth without landing on the moon
