麻风分枝杆菌主要是通过接触传染.（）

一个正n边形的一个内角是它的外角的5倍，则n的值为______．

一细棒处于磁感应强度为B的匀强磁场中，棒与磁场垂直，与水平方向夹角为θ.磁感线水平指向纸内，如图11-42所示，棒上套一个可在其上滑动的带负电的小球C，小球质量为m，带电荷量为q，球与棒间动摩擦因数为μ，让小球从棒上端由静止下滑，求：

图11-42

(1) 小球的最大速度；

(2) 动摩擦因数μ应具备的条件.

第二节 根据对话内容，从对话后的选项中选出能填入空白处的最佳选项，并将答案填写在本题下面的横线上。选项中有两项多余选项。（共5小题；每小题2分，满分10分）

Purser: Excuse me, have you filled out your customs declaration form yet?

Han: No, I haven’t. ___1____

Purser: Yes._____2______

Han: Thanks...It looks rather complicated.

Purser:___3____ ---the Prohibited Articles List and the Duty-Free Quota List. Right.Here.

Han: I have nothing but personal belongings.

Purser:_____4__. But please go over the lists to make sure that you have nothing to declare.

Han: All right. We seem to be standing still.

Purser: ____5____. We’ve waiting for the quarantine (防疫)and immigration(移民) officers to come on board to check the passport and health certificates. There they are now, on that launch.

Han: Well, I’d better hurry and get ready to go ashore. Thank you.

A．In that case, just put down “personal effects”.

B．I can help you. Please look through the two lists.

C．Am I to fill it out before we land?

D．I’d better hurry now.E.Here’s a form for you, sir.

F.The ship is docking(靠码头) soon.

G.What can I do with all my belongings?

药材黄柏来源于（）

A.芸香科

B.樟科

C.柏科

D.木兰科

E.毛茛科