光学谐振腔是激光器的重要组成部分，它的作用是提供轴向的光波模的正反馈以及保证激光器的

Are you ready for adventure (冒险)? Then Sunny Shores Sea Camp is the place for you! The activities there are all about the sea.

At Sunny Shores Sea Camp, you can get excited and improve your skill-level. You can enjoy the wonders of Sunny Island. From diving（潜水）to sailing, sea science to seafood, Sunny Shores Sea Camp offers courses for your different interest. You can also learn about the sea environments of Sunny Island. It is hard for you to find anywhere else like that.

Whether you're a beginner or already an expert (专家), Sunny Shores Sea Camp is a great place that brings together campers from all over the world.

Wonderful memories and new friends are waiting for you at Sunny Shores Sea Camp!

Camp Activities: Adventure . Sea Biology. Diving . Sailing . Windsurfing

Camp Address: Sun Bay , South Florida 000634

Dates: June 28 - July 18 , July 21 -August 9

Cost Week: $600 - $900

Campers Ages: From 13 to 17

Contact us: Sign up at www.sunnyshoresseacamp.org! Or call 800-645-14231

小题1:At Sunny Shores Sea Camp, all the activities are about___________.

A．the earth

B．food

C．science

D．the sea小题2:At Sunny Shores Sea Camp, you can___________.

A．improve your skill-level

B．learn about sailing stories

C．take19 different courses

D．protect the sea environment小题3:The campers are only___________.

A．adults between 18 and 28

B．experts

C．teenagers between 13 and 17

D．beginners

如图所示，在实验室用两端带有竖直挡板C和D的气垫导轨和有固定挡板的质量都是M的滑块A和B做“探究碰撞中的守恒量”的实验，实验步骤如下：

a. 调整气垫导轨，使其水平；

b. 把两滑块A和B紧贴在一起，在A上放质量为m的砝码，置于导轨上，用电动卡销卡住A和B，在A和B固定挡板间放入一轻弹簧，使弹簧水平压缩；

c. 按下电钮使电动卡销放开，同时启动两个记录两滑块运动时间的电子计时器，当A和B与固定挡板C和D碰撞同时，电子计时器自动停表，记下A至C和B至D的运动时间t₁和t₂；

d. 重复几次，取t₁和t₂的平均值。

（1）应测量的数据还有____________；

（2）只要关系式____________成立，即可得出碰撞中守恒量是mv的矢量和。

凡是知道案件情况的单位和个人，是否都有义务出庭作证。（）

A、有义务

B、无义务

C、自己想做证就做证，不愿作证可以拒绝

D、法律无此规定

扶梯检验中，判断梯级与裙板间隙合不合格的检测标准是梯级与裙板两边间隙之和不小于7mm（）

实际设计的照度值和规定的照度标准相比，往往有偏差，GB50034-2004《建筑照明设计标准》规定一般情况下，允许的偏差是（）。

A.不得低于标准值

B.允许+50％～-10％

C.允许+10％～-10％

D.允许+10％～-5％