【判断题】【消耗次数：1】
简单图不含平行边。
①
正确
②
错误
参考答案：
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相关题目
【简答题】
含有平行边的图称为[填空1]。
【单选题】
设G是 n（n≥3)阶m 条边的简单平面图，则下列哪个公式是正确的：
①
m - n + r = 2；
②
m ≤ 2n - 4；
③
m ≤ 3n - 6；
④
m ≤ 4n - 8。
【多选题】
设 G 是 n (n32)阶 n + 1 条边的无向简单连通图, 则以下哪些性质正确：
①
存在顶点 v, d(v)33；
②
所以顶点度数之和等于2(n + 1)；
③
至少有两个顶点不是割点；
④
奇度顶点个数可以不是偶数个。
【单选题】
设 G 是 n (n32)阶 n + 1 条边的无向简单连通图, 则以下哪个性质正确：
①
存在顶点 v, d(v)32；
②
存在顶点 v, d(v)33；
③
存在顶点 v, d(v)34；
④
存在顶点 v, d(v)35。
【单选题】
设 G 是 n (n32)阶 n + 1 条边的无向简单连通图, 则以下哪个性质不正确：
①
存在顶点 v, d(v)33；
②
所以顶点度数之和等于2(n + 1)；
③
至少有两个顶点不是割点；
④
奇度顶点个数可以不是偶数个。
【单选题】
设 n 阶 m 条边的平面图是自对偶图, 则下面哪个式子正确：
①
m = 2n - 4;
②
m = 2n - 2;
③
m = 2n ;
④
m = 2n + 2 。
【单选题】
设 G 是 n 阶 m 条边的简单平面图, 已知 m 30, 则最小度d (G) 满足：
①
d (G) ￡ 3；
②
d (G) ￡ 4；
③
d (G) = 5；
④
d (G) ≥ 5。
随机题目
【单选题】
They have done things they ought_____.
①
not to do
②
not to be done
③
not to have done
④
not having done
【单选题】
____ native to North America, corn has now spread all over the world.
①
In spite of
②
That it is
③
It was
④
Although
【单选题】
Bit by bit, a child makes the necessary changes to make his language ____.
①
as other people
②
as other people’s
③
like other people
④
like other people’s
【单选题】
Please____ me whether I should accept the offer.
①
advise
②
suggest
③
propose
④
direct
【单选题】
All the flights ____ because of the snowstorm, we had
to take the train instead.
①
were canceled
②
had been canceled
③
having canceled
④
having been canceled
【单选题】
A camera takes light rays bounced off objects and____ them
on a sheet of a film.
①
concentrates
②
mixes
③
combines
④
focuses
【单选题】
It has been proposed that we ____ our decision until the next meeting.
①
delayed
②
delay
③
can delay
④
are to delay
【单选题】
By the middle of the 21st century, the vast majority of the world’s population ____ in cities rather than in the country.
①
are living
②
will be living
③
have lived
④
will have lived
【单选题】
Mary tiptoed over and took the clock away
because she hated to hear it ____ when she was
trying to go to sleep.
①
sounding
②
ringing
③
ticking
④
humming