下列化合物按化学位移值的从大到小的顺序排列正确的是（ ）
A: CH3F >CH3Cl> CH4> CH3I
B: CH3F >CH3Cl> CH3I> CH4
C: CH4> CH3I > CH3Cl > CH3F
D: CH3I > CH4> CH3Cl > CH3F
A: CH3F >CH3Cl> CH4> CH3I
B: CH3F >CH3Cl> CH3I> CH4
C: CH4> CH3I > CH3Cl > CH3F
D: CH3I > CH4> CH3Cl > CH3F
举一反三
- 下列化合物按化学位移值的从大到小的顺序排列正确的是( ) A: CH3Br >CH3Cl> CH4> CH3I B: CH3F >CH3Cl> CH3I> CH4 C: CH4> CH3I > CH3Cl > CH3Br D: CH3I > CH4> CH3Cl > CH3F
- 下列各组化合物分子中，键角大小顺序正确的是 A: BeCl<sub>2</sub>>BF<sub>3</sub>=NH<sub>3</sub>>CH<sub>4</sub> B: NH3>CH<sub>4</sub>>BeCl<sub>2</sub>>BF<sub>3</sub> C: CH<sub>4></sub>NH<sub>3</sub>=BF<sub>3</sub>>BeCl<sub>2</sub> D: BeCl<sub>2</sub>>BF<sub>3</sub>>CH<sub>4</sub>>NH<sub>3</sub>
- 判断ch是数字字符的C语言表达式是( ) 。 A: '0' <= ch <= '9' B: ch >= '0' && ch <= '9' C: ch >= '1' && ch <= '10' D: ! (ch < '0' || ch > '9') E: ch >= '0' || ch <= '9'
- 以下哪个选项是判断ch是否为大写字母的正确形式？ A: ch >= 'A' || ch <= 'Z' B: ch >= 'A' AND ch <= 'Z' C: ch <= 'Z' && ch >= 'A' D: 'A' <= ch <= 'Z'
- 下面判断ch是大写或者小写英文字母的表达式哪个正确？ A: ch >= 'A' && ch <= 'Z' || ch >= 'a' && ch <= 'z' B: ch >= A && ch <= Z || ch >= a && ch <= z C: 'A' <= ch <= 'Z' || 'a' <= ch <= 'z' D: A <= ch <= Z || a <= ch <= z