1983 年

In the figure, chords $AB$ and $CD$ intersect at $P$. $BP=DP$. $\angle CAD=$

In the figure, the three sides of $\triangle ABC$ touch the circle at the points $P$, $Q$ and $R$. $\angle PQR=$

If the line $2x-3y+c=0$ passes through the point $(1,1)$, then $c=$

The equation of the line passing through $(1,-1)$ and perpendicular to the $x$-axis is

If $d$ is the distance between the point $(a,b)$ and $(b,a)$, then $d^2=$

The pie chart shows how a boy spends the $24$ hours of a day. If the boy spends $4$ hours playing, how much time does he spend watching television?

There are $12$ boys and $8$ girls in a class. $\dfrac14$ of the boys and $\dfrac14$ of the girls wear glasses. What is the probability that a student chosen at random from the class is a boy not wearing glasses or a girl wearing glasses?

In the figure, $P$, $Q$ and $R$ are curves showing the frequency distributions of the heights of students in three schools, each having the same number of students. Which distribution has the greatest standard deviation and which the smallest?

If $x+\dfrac1x=2+\dfrac12$, then $x=$

$12-x-x^2<0$ is equivalent to