As a study aid, it is convenient, inexpensive and allknowing.
作为一个学习工具，字典非常方便、便宜而且知识全面。
There is only one small, "un-blinded" study without placebos or control subjects that advocates point to as evidence that smokeless tobacco works as a smoking cessation aid.
只有小部分人支持非盲法研究没有对照或者控制组，并认为无烟烟草有助于戒烟。
应用推荐