下述上颌第二前磨牙与上颌第一前磨牙形态区别中错误的是（） A.上颌第二前磨牙的颊尖比

( )可能使网桥反复转发同一个帧，增加网络不必要的负荷。

阅读理解。

     Maria: I'm in Grade Seven. After school I like listening to music or watching TV at home. I also go

dancing with my friends. We always have much fun.

     Jack: I'm a student in Grade Eight. I do many different things after school.  I play on the  computer,

watch a movie, play football, do homework, read or play outside with some friends.  

     Tom:   I'm in Grade Nine.  After school I love to have football practice.  It  is very  fun.  During the

weekend, I always spend time with my friends. We listen to music and watch movies together.

     Helen: I am a student of Grade Eight. After school I usually go with my friends to the park and then

we all play volleyball there. After that we like to rest by the river in the park.

     Peter: I'm a student in Grade Nine. After school, I can do a lot of things. Having fun with my friends,

riding a bike, going to the beach, watching TV, playing on the computer,  swimming or walking  around.

My favourite is going to the beach.

1. Maria likes to ______ with her friends after school.

A. watch TV  

B. listen to music  

C. dance    

D. ride

2. Jack is in Grade ______ this year.

A. Seven      

B. Eight      

C. Nine      

D. Ten

3. ______ like to play football after school.

A. Jack and Tom      

B. Jack and Helen    

C. Tom and Peter

D. Tom and Helen

4. Helen usually goes to ______ after school.

A. the cinema    

B. the park    

C. her friend's home    

D. the beach

5. Which one is TRUE?

A. Helen and her friends enjoy fishing by the river.

B. Tom and Peter are students of Grade Eight.

C. Tom and his friends like to watch movies on the weekend.

D. Peter never plays with his friends after school.

暴露组与非暴露组医院感染率之比称为（）

A.相对危险度

B.医院感染患病率

C.罹患率

D.医院感染发病率

E.比值比

小建中汤是在桂枝汤的基础上（）

A.去芍药

B.倍用甘草、芍药

C.倍用芍药并加饴糖

D.倍用甘草加饴糖

E.去芍药加饴糖

Windows NT操作系统内置4种标准网络协议；TCP/IP协议、MWLink协议、NetBIOS的扩展用户接口(NetBEUI)和___________。