As the chief center of the American War of Independence,______was called "birthplace of America".
A. New York
B. New England
C. New Jersey
D. Washington D.C.
软膏剂中加入硅酮起什么作用()
A. 润湿剂
B. 溶剂
C. 防腐剂
D. 表面活性剂
E. 防水剂
下列关于软膏基质的叙述中错误的为()
A. 液状石蜡主要用于调节软膏稠度
B. 水溶性基质释药快，能与渗出液混合
C. 凡士林中加入羊毛脂可增加吸水性
D. 硬脂醇是W／O型乳化剂，但常用于O／W型乳化基质中起稳定、增稠作用
E. 水溶性基质由水溶性高分子物质加水组成，需加防腐剂，但不需加保湿剂
The main purpose of the passage is to
A. offer advice on how to cure a variety of common ailments of astronauts.
B. show the possibility of genome technology use in keeping astronauts fit.
C. discuss the seriousness of most astronauts" different health problems.
D. identify the causes of the genetic damage in the DNA of astronauts.
微信支付 
支付宝支付