以下非法的赋值语句是( )。
A.n=(i=2,++i);
B.j++;
C.++(i+1);
D.x=j>0;
参考答案:C
解析:自加或自减运算的操作数不能是表达式。
在下列各句的空白处填入一个适当的词,使句子意思完整、语法正确。
1. How q______ time passed. I've been in my hometown for two months.
2. It's our d______ to protect (保护) the environment.
3. I think this dictionary is h______ for your study.
4. Hurry up, or we won't c______ the early bus.
5. Don't be scared to make m______ when you speak a foreign language.
如图所示,半球形容器固定在水平面上,O为球心,一质量为m的小滑块静止在P点,OP与水平方向的夹角为θ。滑块所受支持力为F,所受摩擦力为f。下列关系正确的是 ( )
A.
B.
C.
D.