【单选题】下列羟基酸受热脱水,能生成α,β-不饱和酸的是( )。
【单选题】Part B Listening Comprehension Directions: In this part of the test there will be some short talks and conversations. After each one, you will be asked some questions. The talks, conversations and que...
A.
It's up to fifteen pages.
B.
It's made by a professional organization covering nearly all parts of married life.
C.
It states in advance how many children they will have and where they'll live.
D.
It includes in advance the detailed rules to follow in nearly every part of the married life.
【判断题】β-羟基丁酸受热发生分子内脱水生成α,β不饱和酸。
【单选题】下列哪种类型的羟基酸受热发生分子内脱水,生成不饱和酸?
【单选题】Part B Listening Comprehension Directions: In this part of the test there will be some short talks and conversations. After each one, you will be asked some questions. The talks, conversations and que...
A.
It is neither a relaxing nor stylish wear.
B.
It will come off frequently in walking.
C.
It is old-fashioned as it is only worn by old women.
D.
It will bring great difficulty to dally work.
【单选题】由于内扩散的影响,使得固体催化剂颗粒中反应物的浓度降低,内扩散对复合反应选择性的影响有以下的结论( )
D.
对于一级连串反应,内扩散的作用使得瞬时选择性降低
【单选题】Part B Listening Comprehension Directions: In this part of the test there will be some short talks and conversations. After each one, you will be asked some questions. The talks, conversations and que...
A.
They have been accustomed to being obedient to their parents and teachers.
B.
They naturally do not need instant gratification before starting to do anything.
C.
They know they must sit down and work hard before making any progress.
D.
They are repeatedly told by their parents, friends and neighbors to do so.
【单选题】Part B Listening Comprehension Directions: In this part of the test there will be some short talks and conversations. After each one, you will be asked some questions. The talks, conversations and que...
A.
To sign trade agreements respectively with France.
B.
To send some war material to Vietnam.
C.
To pull France out of its trouble in Indochina.
D.
To give France strong moral support in Indochina.