【单选题】苔藓植物具: A. 真根 B. 假根 C. 既有真根又有假根 D. 无根只有鳞片
【判断题】磁性物质由于磁化所产生的磁场不会随着外磁场的增强而无限的增强。
【判断题】磁性物质由于磁化所产生的磁化磁场不会随着外磁场的增强而无限的增强。当外磁场增大到一定程度时,磁性物质的全部磁畴的磁场方向都转向与外部磁场方向一致,磁化磁场的磁感应强度将趋向某一定值。
【单选题】What is the man's problem?
A.
He is too busy to finish his assignment in time.
B.
He does not know what kind of topic to write on.
C.
He does not understand the professor’s instructions.
D.
He has no idea how to proceed with his dissertation.
【单选题】What is the man's reaction to the apartment?
A.
He's unimpressed by what the woman told him.
B.
He doubts he can afford it.
C.
He doesn't think it's suitable for him.
D.
He's enthusiastic about it.
【多选题】What is the man's opinion
A.
What children should do is to study.
B.
Children need sufficient sleep.
C.
Children need to do homework.
D.
Part-time jobs make children tired.
【单选题】磁性物质由于磁化所产生的磁化磁场不会随着外磁场的增强而无限的增强。当外磁场增大到一定程度时,磁性物质的全部磁畴的磁场方向都转向与外部磁场方向一致,磁化磁场的磁感应强度将趋向某一定值,这种磁性能是( )