问题
单项选择题
关于氟牙症的临床表现错误的是()。
A.多见于恒牙,若发生于乳牙,程度亦轻
B.白垩色斑、云雾状,其分布与釉质生长线不相吻合
C.对摩擦耐受性差
D.对酸蚀抵抗力弱
E.严重的慢性氟中毒者,可有骨骼的增殖性变化
答案
参考答案:D
关于氟牙症的临床表现错误的是()。
A.多见于恒牙,若发生于乳牙,程度亦轻
B.白垩色斑、云雾状,其分布与釉质生长线不相吻合
C.对摩擦耐受性差
D.对酸蚀抵抗力弱
E.严重的慢性氟中毒者,可有骨骼的增殖性变化
参考答案:D
根据所给短文的意思,用下面文本框中所给单词或短语的正确形式填空。(文本框中所给单词或 词组有多余) | |
of the People's Republic of China, the Ministry of Education released (发布) its "Sunny Sports long-distance winter run" program (阳光体育冬季长跑). From October to April, Chinese students have to be 1______ to run a certain distance every day. The 2______ distance for elementary students is 1,000 meters a day, 1,500 meters for middle school students, and 2,000 meters for high school and college students. Some people think that such an 3______ activity will do good to Chinese students. For one thing, it lifts the spirit and builds confidence. For another, it helps you learn new things and remember old information better. More importantly, it is a good idea to develop and improve the 4______ of education. However, other people like parents 5______ the time and energy that it takes the students to work on their academic performances (学业情况) and physical activities. It is obvious that there are more advantages of taking exercise than its disadvantages. Don't be a couch potato! Get out there and run. |