如图所示,在一粗糙水平面上有两块质量分别为m1和m2的木块1和2,中间用一原长为l、

题型:单项选择题

问题:

如图所示,在一粗糙水平面上有两块质量分别为m1和m2的木块1和2,中间用一原长为l、劲度系数为k的轻弹簧连接起来,木块与地面间的动摩擦因数为μ.现用一水平力向右拉木块2,当两木块一起匀速运动时,两木块之间的距离是()

A.

B.

C.

D.

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Researchers at the University of Arizona, led by Teresa Cummins, conducted an exploratory study on the online learning modules, designed to supplement hands-on classes taught by local experts and supported by an overview text, to help users increase their understanding of key concepts in the Arizona Master Watershed Steward program. They also sought to determine whether program participants would use the non-compulsory modules.

Their evaluation revealed that module users increased their understanding of key watershed concepts; participants in the evaluation demonstrated a 30 percent increase in content knowledge following module use. Additionally, 70 percent of participants retained this knowledge through a two-month follow-up test.

A follow-up survey showed that approximately half of the participants returned to the online modules on their own; several of these users returned several times and spent multiple hours per session. Comments from the follow-up survey suggested that the users accessed the site either as they had the time or as they needed the information.

Online usage statistics indicated participants continued to visit the site for many months following the modules’ release and advertisement. Though many visits were very brief (a single pageview; only a couple of seconds), visitors with many returns to the site and/or long visits appeared to be working through the modules.

One participant stated, "My brain can only hold so much information; the modules keep information on-hand." Other participants commented that the modules were "more interesting and interactive" than the text material, and a "very effective tool" and "a great resource to the Master Watershed Steward community."

The Arizona Master Watershed Steward program, sponsored by University of Arizona, prepares adults to serve as volunteers in the conservation of water resources and the protection, restoration, and monitoring of their watersheds. The modules were intended to reinforce concepts covered in classes and further engage participants in the learning process.

One key finding was that the modules were not clearly preferred by users over in-person instruction. One participant stated, "For me, they are just another avenue for learning, a supplement or additional reference. I prefer in person and real hands-on learning." Other participants similarly expressed their desire for hands-on and face-to-face interaction. Several participants noted that the usefulness of in-person lectures—was a function of the presenter.

Overall, the exploratory evaluation indicated that the modules were a welcome supplement to the course and were effective in reinforcing key concepts. Participants retained knowledge for several weeks, although since subjects were self-selected, they may have been self-motivated to pay attention and master the online module materials.

"I am constantly searching for new ways to educate our program’s diverse audiences and reinforce watershed science concepts, " says Candice Rupprecht, state coordinator for the Master Watershed Steward program. "I am excited to know that online learning modules can enhance our program by offering additional independent learning opportunities for our volunteers.

Which of the following is the text mainly about()

A. In-person classroom learning and online learning

B. The pros and cons of online learning

C. Effective research tools to study the program

D. Online learning as a supplement of watershed program

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男性,30岁,搬家公司工人,工作时不慎被家具砸伤右前臂,18小时后急诊来院,诉右前臂疼痛剧烈,右手主动活动障碍。查体见右前臂明显肿胀、压痛

如治疗不及时,晚期可遗留怎样的体征()

A.右侧屈腕屈指畸形

B.右侧伸腕伸指畸形

C.右前臂旋转功能障碍

D.右手出现雷诺现象

E.少尿

题型:单项选择题

甲、乙类油品埋地卧式油罐的通气管管口应高出地面()及以上。

A、10m

B、8m

C、6m

D、4m

题型:单项选择题

低倍数泡沫系统是指系统产生的灭火泡沫倍数()的系统。

A.低于10

B.低于30

C.低于15

D.低于20

题型:单项选择题

根据《开发区规划管理办法》的规定,开发区的土地利用和各项建设必须( )。

A.符合开发区总体规划,服从统一的规划管理
B.符合开发区详细规划,服从详细的规划管理
C.符合开发区规划,服从统一的规划管理
D.符合开发区规划,服从详细的规划管理

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