Questions

Night and Day.

Night is what that always falls but never breaks

Day is what always breaks but never falls.

Eating raises blood sugar levels, insulin stimulates the lowering of blood sugar level. In this example the response to the stimulus (increased blood sugar levels) opposes that stimulus (by lowering blood sugar levels).

Plants wilt due to excess of Transpiration.

The strength of an electromagnet can be increased by increasing the cross-sectional area, increasing the number of turns, increasing current supply, increasing the length of the coiled wire.

A Windmill.

A credit card's interest rate is the price you pay for borrowing money. For credit cards, the interest rates are typically stated as a yearly rate. This is called the annual percentage rate (APR). On most cards, you can avoid paying interest on purchases if you pay your balance in full each month by the due date.

Your APR is expressed in terms of a year, but credit card companies use it to calculate charges over your monthly statement period.

The given sentence is in simple past. No improvement required.