发动机异响主要影响因素不包括()
A. 电压
B. 润滑条件
C. 温度
D. 转速
To help the listeners connect what they have heard with their own ideas and experience andmove from listening to another skill is () stage.
A. post-listening
B. pre-listening
C. while-listening
D. after-listening
Before listening, it's important to prepare students for listening. What activities can we use in pre-listening stage?
A. Predicting
B. Note-taking
C. Setting the scene
D. Inferring
体内蛋白质和许多重要酶的巯基均直接来自哪种氨基酸
A. 苯丙氨酸
B. 半胱氨酸
C. 胱氨酸
D. 鸟氨酸