问题
单项选择题
牙石中最主要的成分是()
A.有机物
B.无机盐
C.细菌
D.食物残渣
E.脱落的上皮细胞和水
答案
参考答案:B
牙石中最主要的成分是()
A.有机物
B.无机盐
C.细菌
D.食物残渣
E.脱落的上皮细胞和水
参考答案:B
用方框中所给的词的适当形式填空,使短文正确、通顺。每词限用一次。
The Chinese always like staying together and talking very 小题2:______ _," Dai Bin of the China Tourism Academy said. Zhang Minjie, a tour guide, was embarrassed (尴尬的) when he led a group of Chinese tourists小题3: Singapore. "A young man spit his gum out. When he was leaving, the police 小题4: him, and fined him," Zhang told Qianjiang Evening News. Some Chinese also 小题5: everywhere and jump queue(插队). Some like to write on小题6: buildings, and smoke in non-smoking areas. 小题7:_______ of these problems help the reputation(名声) of Chinese people traveling abroad. However, there are still a lot of thoughtful Chinese tourists, 小题8:_______ behave respectfully when visiting the places of interest, taking a few 小题9:_______ before moving on to the next spot. 小题10:_______ we spend money to enjoy ourselves, it doesn't mean we can do anything we want. All travelers should respect local customs and take care of the environment. |