GCSE Study Guide 2026

Subject-verb agreement dictates that a singular subject requires a singular verb. In option C, "An electrical phenomenon" is a singular subject, and the verb "is" correctly agrees with it. Options A, B, and D contain singular subjects ("layer," "training," "soil") paired incorrectly with plural verbs ("cover," "focus," "dry out").

Bubble sort passes through the list repeatedly, swapping neighboring elements until the entire list is sorted.

Newton's Third Law states that for every action there is an equal and opposite reaction, which causes both skaters to move apart.

Momentum = mass × velocity = 0.5 kg × 6 m/s = 3 kg·m/s.

From F = ma, if F doubles and m is constant, then a must double to maintain the equation.

The number of real solutions can be determined by the discriminant, b² - 4ac. For this equation, a=4, b=-12, and c=9. The discriminant is (-12)² - 4(4)(9) = 144 - 144 = 0. When the discriminant is equal to 0, there is exactly one real solution (also known as a repeated root).