子曰：“饭疏食，饮水，曲肱而枕之，乐亦在其中矣。不义而富且贵，于我如浮云。”（《论语》）

    庄子钓于濮水，楚王使大夫二人往请，曰：“愿以境内累矣！”庄子持竿不顾，曰：“吾闻楚有神龟，死已三千岁矣，王以巾笥^①而藏之庙堂之上。此龟者，宁其死为留骨而贵乎？宁其生而曳尾于涂中乎？”二大夫曰：“宁生而曳尾涂中。”庄子曰：“往矣！吾将曳尾于涂中。”（《庄子》）

【注解】①巾：覆盖用的丝麻织品。这里名词用作动词，用锦缎包裹。笥：一种盛放物品的竹器。名词用作动词，用竹匣装。

    “USA? Britain? Which country is____(good) to study in?” We often hear such discussion. As China opens its door, it is a dream for many Chinese students to study abroad. They want to learn about the outside world.

    It's true that studying abroad can help students develop____(they). Their foreign language skills will____ (improve) and it may be easier to find jobs.

    But there are problems____ should be considered. Language is the first. Students must spend a lot of time____ (learn) another language.

    Students must also learn____ (live) without parents' care and deal with all kinds of things they didn't have to do before, like looking after themselves. There are ____ (report) about Chinese students abroad running into an ocean of difficulties____ giving up in the end. When they have to take care ____ themselves, it is hard for students to study well.

    Finally, studying abroad brings a heavy burden to the family. For most Chinese parents, the cost of studying abroad____ (be) very high. But is it worth it?

据经纬网图，完成后面小题：

如图所示，木块B上表面是水平的，木块A置于B上，一起以某一初速度沿光滑斜面向上冲，上冲过程中A与B保持相对静止，在向上运动的过程中（   ）