AP计算机教程4-6：中等多选题

Which of the following expressions is equivalent to !(c || d) ?

Which of the following is equivalent to the code segment below?

if (x > 2) x = x * 2;
if (x > 4) x = 0;

Which of the following is equivalent to the code segment below?

if (x > 0) x = -x;
if (x < 0) x = 0;

At a certain high school students receive letter grades based on the following scale.

Which of the following code segments will assign the correct string to grade for a given integer score?
I.

if (score >= 93) grade = "A";
if (score >= 84 && score <= 92) grade = "B";
if (score >= 75 && score <= 83) grade = "C";
if (score < 75) grade = "F";

II.

if (score >= 93)
 grade = "A";
if (score >= 84)
 grade = "B";
if (score >=75)
 grade = "C";
if (score < 75)
 grade = "F";

III.

if (score >= 93) grade = "A";
else if (score >= 84) grade = "B";
else if (score >= 75) grade = "C";
else grade = "F";