第二部分：词汇知识运用（共两节，满分30分）
第一节：多项选择（共10小题；每小题1分，满分10分）
从A、B、C、D四个选项中，选出可以填入空白处的最佳选项，并在答题卡上将该项涂黑。
21. None of us was good at swimming, so the crossing of this dangerous river was really a _____.
A．motivation B．symptom C．conflict D．challenge
22．The example to which the students had to apply what they’d learned was______,not abstract.
A．absolute B．awkward C．mental D．concrete
23．Drinking water, having a healthy snack and taking exercise are all positive ways to _____ you when you are working on a tight schedule．
A. reuse B. refresh C. relief D. release
24．Young people use more web language in their conversations, such as Geili because such language gives them a sense of ____．
A. unity B. identity C. responsibility D. security
