单词拼写  (用单词的正确形式填空) （共10小题，每小题0.5分，满分5分）
You need to have a large v_______ as well as a good knowledge of grammar in order to learn English well.
Shanghai, as a c_______ center in the east of China, attracts thousands of business people every year.
Peng Liyuan shows great c________ for children suffering from AIDS and often visits and comforts them.
Many customers have c_______ a lot to the company about the low quality of their products recently.
All the students in our school have a_______ to the library and the Internet center.
Your experiences as a _______ (志愿者) matter a lot when applying for a foreign university.
As an English learner, you need to know how to _______(辨别) between American English and British English.
President Xi Jinping paid an _______(官方的，正式的) visit to Russia recently to improve the friendly and cooperative relations between the two countries.
His interest in this subject _______(逐渐地) decreases as the teacher isn’t able to make the lessons lively.
There was a terrible explosion in Boston on April 16^th. People there _______(恐慌) at the sound of the explosion.