人口迁移原因
参考答案:
经济、政治、国际战争、国内战争、社会秩序的变革和文化因素、生态环境的变化、希望接受良好的教育、逃避种族歧视、结婚或离婚、退休、避寒、避暑、疗养等。
研究表明,运用葡糖酶防龋,并不是因为该酶()
A.可减少菌班数量
B.可破坏葡聚糖的形成
C.可影响细菌的代谢过程
D.可降低菌班的黏附能力
Which of the following is not one of the responsibilities of the Tariff Commission.()
A. To formulate the guideline for drawing up the regulations.
B. To set temporary tariff rates.
C. To levy Customs tariffs on imports & exports.
D. To examine the draft of the amendment to tariff.