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【单选题】For more than thirty years after astronauts first set foot on the Moon, scientists have been unable to unravel the mystery of where the Earth’s only satellite came from. But now there is direct eviden...
A.
the differences between the Earth and the Moon
B.
how man manages to set foot onto the Moon
C.
the collision between the Earth and the Moon
D.
the origin of the Moon
【单选题】9SiCr中碳的平均质量分数约为( )。
A.
0.009000000000000001
B.
9.0E-4
C.
0.09
D.
8.999999999999999E-5
【单选题】Mars fascinates scientists because of its similarity to Earth, and it fascinates the public because our myth of "Martians" is a vision of life beyond Earth. The Mars 62 continues with the launch of ...
A.
extremes
B.
extracts
C.
terminals
D.
radicals
【单选题】Mars fascinates scientists because of its similarity to Earth, and it fascinates the public because our myth of "Martians" is a vision of life beyond Earth. The Mars 62 continues with the launch of ...
A.
thus
B.
however
C.
so
D.
but
【单选题】The History of the Atomic Bomb On August 2, 1939, just before the beginning of World War II, Albert Einstein wrote to then President Franklin D. Roosevelt. Einstein and several other scientists told R...
A.
Franklin D. Roosevelt.
B.
Nazi Germany.
C.
Albert Einstein and other scientists.
D.
The Second World War.
【单选题】Mars fascinates scientists because of its similarity to Earth, and it fascinates the public because our myth of "Martians" is a vision of life beyond Earth. The Mars 62 continues with the launch of ...
A.
explore
B.
explode
C.
exploit
D.
deplore
【单选题】同位素（）
A.
质子数与中子数均相同，且原子核处于相同能量状态的一类原子
B.
具有相同质子数的一类原子
C.
质子数相同但中子数不同的核素
D.
质子数与中子数均相同，但原子核处于不相同的能量状态的核素
E.
原子核处于不稳定状态，需要通过核内调整或能级调整才能趋于稳定的核素
相关题目：
【判断题】自然界中碳有三种同位素：碳-12，碳-13和碳-14。
A.
正确
B.
错误
【单选题】For more than thirty years after astronauts first set foot on the Moon, scientists have been unable to unravel the mystery of where the Earth’s only satellite came from. But now there is direct eviden...
A.
the differences between the Earth and the Moon
B.
how man manages to set foot onto the Moon
C.
the collision between the Earth and the Moon
D.
the origin of the Moon
【单选题】9SiCr中碳的平均质量分数约为( )。
A.
0.009000000000000001
B.
9.0E-4
C.
0.09
D.
8.999999999999999E-5
【多选题】天然铀有哪几种同位素()
A.
铀234
B.
C.
铀236
D.
铀238
【单选题】下列互为同位素的一组是
A.
和
B.
和
C.
和
D.
和
【单选题】连铸机结晶器用Cs-137同位素检测结晶器内( )。
A.
凝固层厚度
B.
钢水质量
C.
钢液面高度
【单选题】同位素中（）。
A.
质子数相同，中子数不同
B.
质子数相同，中子数相同
C.
中子数相同，质子数不同
D.
中子数、质子数均不相同
【单选题】The History of the Atomic Bomb On August 2, 1939, just before the beginning of World War II, Albert Einstein wrote to then President Franklin D. Roosevelt. Einstein and several other scientists told R...
A.
Franklin D. Roosevelt.
B.
Nazi Germany.
C.
Albert Einstein and other scientists.
D.
The Second World War.
【单选题】下面哪组属于同位素 ()
A.
和
和
B.
和
和
C.
和
和
D.
和
和
【单选题】今有氧的同位素16O、17O、18O，氢的同位素H、D，从水分子的原子组成来看，可组成的水分子可以有
A.
3种
B.
6种
C.
9 种
D.
12种
【单选题】同位素（）
A.
质子数与中子数均相同，且原子核处于相同能量状态的一类原子
B.
具有相同质子数的一类原子
C.
质子数相同但中子数不同的核素
D.
质子数与中子数均相同，但原子核处于不相同的能量状态的核素
E.
原子核处于不稳定状态，需要通过核内调整或能级调整才能趋于稳定的核素