题干

如图所示是一款人字梯,为了防止展开后滑动,需要在安装孔处安装拉杆。要求人字梯展开和收拢时操作方便,并且收拢后拉杆不伸出梯子。下列拉杆的结构方案中合理的是(   )

A:

B:

C:

D:

上一题 下一题 0.0难度 选择题 更新时间:2018-06-27 09:40:35

答案(点此获取答案解析)

B

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书面表达

假如你是Kevin,正和朋友们在北京旅游。请给你父母写一封电子邮件.告诉他们你在北京旅游的情况。要求:语句通顺、前后连贯;60词左右。邮件的开头已经给出。

From: kevin@ 163. com

To: hbmrs@ sina. com

Subject: Trip

Date: May 15, 2013

Dear Mom and Dad,

I am writing this e-mail to tell you my trip to Beijing.                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                                    

Love,

Kevin