How do you spend your time at school? Do you know how students in other countries study every day? Here are the studying ways in some western schools.

American Students

    American students spend seven hours in their schools every day. And the day is divided（划分） into classes of about 40 to 50 minutes. Students study English, history, math, science, art and foreign languages. They go to listen to different lessons taught by different teachers in different classrooms. After class they learn job skills. Sometimes they study by working in an office, a hospital or other places one day a week.

German Students

    German students love practicing. Lots of schools have lessons for only half a day. They spend most time practicing. Teachers give students enough freedom. Students may try all kinds of ideas they have. They begin to plan what they will do in the future and work hard at a young age.

French Students

    French students like independence（独立） and freedom. Their school life is very relaxing and interesting. When they have tests, they may have snacks. For example, they can put a few desks together, and put some peanuts （花生）or candies on them.

现代旅游的特点：主体____，形式____，空间____，目的____。

指出下列史实的错误，并加以改正。

设命题设命题$p$：$\exists n\in N$，则$n^2$＞$2^n$，则$\neg p$为(     )

立方根等于3的数是（　　）