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【单选题】
Look! The boy on the beach.A.
lie
B.
lies
C.
lying
D.
is lying
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皮皮学刷刷变学霸
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【单选题】I'll call you tonight at 10 o'clock ______ I can find a telephone that works.
A.
unless
B.
suppose
C.
provided
D.
when
【单选题】短周期元素A、B、C、D在周期表中的位置如图所示，若A的原子序数为a、最外层电子数为n，则下列关系式或说法错误的是（ ） A B C D
A.
四种元素的原子序数之和Z=4a+16
B.
四种元素的原子序数之和Z≤50
C.
四种元素的最外层电子数之和E=4n+2
D.
四种元素的最外层电子数之和E≤30
【判断题】天然气和空气混合，当天然气浓度在一定范围内时，遇明火就会发生燃烧和爆炸。燃烧时，燃烧波的传播速度较慢，约0.3～2.4m/s，而爆炸时，会迅即产生高压高温，波速达到1000～3000m/s，对管线和容器的破坏力很大。天然气产生爆炸的浓度范围为5～15％，随温度、压力升高，爆炸浓度的上限提高，爆炸范围扩大。Natural gas and air mix, when the concentration...
A.
正确
B.
错误
【简答题】Fuel gases are very combustible and can easily explode. Explosions can occur when a gas leaks from its container and reaches an ignition source, such as an open flame or spark. In the United States, m...
【简答题】李老师昨天批改了13篇作文，今天批改的篇数是昨天的2倍，结果还剩11本没批改．那么李老师所教的这个班共有多少人？
【单选题】A: 'Bye, darling. Have a good trip. I'll miss you. B: I'll miss you, too. I'll call you every day.
A.
public space
B.
social space
C.
personal space
D.
intimate space
【单选题】听力原文：W: How long will it take you to fix my watch? M: I'll call you when it's ready. But it shouldn't take longer than a week. What is the probable relationship between the two speakers?
A.
Librarian and student.
B.
Operator and caller.
C.
Boss and secretary.
D.
Customer and repairman.
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