When is it o. k. to shift tenses in a sentence?

When people are asked to recall a list of words they had earlier memorized, they often substitute synonyms for some of the words on the original list. this best illustrates the impact of:

How can behavioral science be applied in improving public health? a.by tracking a disease to determine its sourceb.by creating promotions that improve health habitscboth by tracking a disease to determine its source and by creating promotions that improve health habitsd.neither by tracking a disease to determine its source or by creating promotions that improve health habits

The basketball crashed against the backboard, and point guard sheena lunged for it. as she snatched the ball out of mid-air, the crowd cheered, chanting encouragement for her team, the monarchs. so far, the game had been a disaster. with 15 seconds left to go in the final quarter, the monarchs were 2 points shy of victory. what main idea do the details in the passage suggest? the point guard sheena was not a very good player. the monarchs had never lost a basketball game. the monarchs were worried about losing. the crowd was not supporting the monarchs.