Have you imagined spending a night in a museum? Fortunately, your dream may come true. 

Spy Museum|Washington, DC

The Spy Museum is about the unseen jobs and displays spy objects in the world! "Operation Secret Sleepover" invites a group of juniors and parents for a night of detective(侦探) training, like inventing a fake name, gathering intelligence(情报), studying questioning techniques, and more. The next mission starts on Friday, September 9.

Ages：9 to 13

Cost：$115 for general admission/$105 for members

Baseball Hall of Fame | Cooperstown, New York

Fans of America's hobbies will take the chance to stay a few extra nights here. Travel along the hallowed galleries; enjoy a screening in the Grandstand Theater; show your respect to honoring legendary players. Dates sell out quickly. To secure your spot, call (607)547-0329.

Ages: 7 to 12

Cost：$50 for general admission

Milwaukee Public Museum|Milwaukee, Wisconsin

The overnight at Milwaukee Public Museum is intended for the 21＋ crowd. Tickets include dinner, two drinks, snacks, special tours, films in the six-story theater, entry to the new traveling exhibit "Maya：Hidden Worlds Revealed", and continental breakfast. The next event is October 20. Registration closes two weeks prior(提前).

Ages: 21＋

Cost：$125 for general admission

Baltimore National Aquarium | Baltimore, Maryland

Ocean and shark lovers will be glad to spend nights at BNA. Dive into the attractive underwater world and discover the importance of these incredible creatures. Join experts for a behind-the-scenes tour, interact with marine life, and watch a 4D film. 

Ages：8＋

Cost：$120 for general admission/$100 for members

High school students perform(表现) better on tests if they are in a classroom with a view of a green space, instead of a windowless room or a room with a view of built-up space, according to research from the University of Illinois Department of Landscape Architecture. 

"It is the first to show a relationship between studying with a green view and students' performance, " said William Sullivan, head of the research team. "It's a significant finding that if you have a green view outside your window, you'll do better on tests. " Sullivan hopes the results of their research will lead to some changes. "Changes in school design, for example, would be a much better thing than any of the things we spend money on in secondary education today, " Sullivan said.

The research included 94 students at five central Illinois high schools. Students were randomly assigned(随机分配) to one of three kinds of classrooms—windowless, with a window looking out onto built-up space, or with a window looking out onto green space. Each kind of classroom had almost the same size and layout(布局). The students took part in one-on-one experiments in which they did 30 minutes of activities that included a proofreading(勘校) exercise, a speech and a math exercise. Following the activities the students were given an attention test which asked them to repeat a series of(一连串) numbers. 

The findings: Students did better on both study activities and the attention test if they were in a classroom with a green view, Sullivan said. 

The researchers suggest their findings can help planners and policymakers improve students' health and learning. For example, planners can choose places for new schools that already have trees, or they can plant many trees on the site; architects can design classroom windows so they look onto green spaces.