8×18÷8×18=（　　）

​如下哪个表达式同(A>8)&&(A&#91;18)是等价的？​​Which of the following expressions is equivalent to (A&#93;8)&&(A<18)?​ A: !(A<8)&&!(A>18) B: !(A<=8)&&!(A>=18) C: !(A>8||A<18) D: A<8||A>18

‌如下哪个表达式同A>8 AND A&#91;18是等价的？‏‌Which of the following expressions is equivalent to A &#93; 8 AND A < 18?‏ A: NOT（A<8）AND NOT（A>18） B: NOT（A<=8）AND NOT（A>=18） C: NOT（A>8 OR A<18） D: A<8 OR A>18

中国大学MOOC: 如下哪个表达式同A>8 AND A<18是等价的？Which of the following expressions is equivalent to A > 8 AND A < 18?a. NOT（A<8）AND NOT（A>18）b. NOT（A<=8）AND NOT（A>=18）c. NOT（A>8 OR A<18）d. A<8 OR A>18

-18的绝对值是（　　） A: 18 B: -18 C: 8 D: -8

如下哪个表达式同A＞8 AND A＜18是等价的？ which of the following expressions is equivalent to a＞ 8 AND A ＜ 18？ a. NOT（A＜8）and not（a＞18） b. NOT（A＜=8）and not（a＞=18） c. NOT（A＞8 OR A＜18） d. A: a B: b C: c D: d

如下哪个表达式同A>8 AND A&#91;18是等价的？Which of the following expressions is equivalent to A &#93; 8 AND A &#91; 18?a. NOT（A<8）AND NOT（A&#93;18）b. NOT（A&#91;=8）AND NOT（A&#93;=18）c. NOT（A>8 OR A&#91;18）d. A<8 OR A&#93;18 A: a B: b C: c D: d

如下哪个表达式同A>8 AND A&#91;18是等价的？a. NOT（A<8）AND NOT（A&#93;18）b. NOT（A&#91;=8）AND NOT（A&#93;=18）c. NOT（A>8 OR A&#91;18）d. A<8 OR A&#93;18 A: a B: b C: c D: d

They are building the dam in ________ with another firm.

18-8钢中18代表_____,8代表_____ A: 18%的铬 B: 18%的碳 C: 8%的镍 D: 8%的铁