小题1:The purpose(目的) of this notice is____________．

A．to ask people to visit the springs

B．to make visitors know the area

C．to tell visitors what not to do

D．to tell the visitors to have a rest小题2:The notice is written for____________.

A．visitors

B．children

C．workers

D．managers小题3:____________is NOT mentioned in the notice．

A．How long visitors can stay in the area

B．What visitors cannot bring to the area

C．Who looks after the visitors’ things

D．Whether smoking is allowed in the area小题4:The Chinese meaning for “slippery” is____________．

A．平坦的

B．湿滑的

C．狭窄的

D．冰凉的

下列说中正确的是[ ]

A. 氢原子由较高能级跃迁到较低能级时，电子动能减小，原子势能增大

B. 放射性元素的半衰期是指大量该元素的原子核中有半数发生衰变需要的时间

C. 同一元素的两种同位素具有相同的质子数    

D. 中子与质子结合成氘核时吸收能量