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【单选题】
The duration of effective refractory period of ventricular muscle depends mainly on（ ）
A.
The level of the end of an action potential repolarization
B.
The rate of the action potential depolarizes at phase 0
C.
The level of threshold potential
D.
Sodium-potassium pump function
E.
The duration of phase 2 of action potential
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举一反三
【单选题】The basic structural units of skeletal muscle contraction and relaxation are:（ ）
A.
H band
B.
Light band
C.
Segment between two adjacent M lines
D.
dark band
E.
Sarcomere
【多选题】Factors that promote energy metabolism increase include（ ）
A.
Mental stability
B.
The environment is hot
C.
Eating
D.
Muscle movements
E.
Cold environment
【单选题】After the original urine passes through which of the following parts, its composition will not change and become final urine（ ）
A.
Distal convoluted tubules
B.
Collecting duct
C.
Descent branch of loop of medullary
D.
The ascending branch of loop medullary
E.
Proximal tubule
【单选题】Which of the following is true about nearsightedness?（ ）
A.
Weak refraction of the eye can occur
B.
nearer than normal people
C.
Most of them are caused by too short anterior and posterior diameter of the eyeball
D.
Image behind the retina
E.
It is necessary to wear convex lens for correction
【单选题】The following characteristics of synaptic transmission are stated correctly（ ）
A.
Non-summation
B.
Fast transmission speed
C.
Synaptic delay
D.
Bidirectional transmission
E.
Not easy to fatigue
【单选题】The most effective digestive fluid for fat and protein digestion is（ ）
A.
Pancreatic juice
B.
Gastric juice
C.
Small intestinal juice
D.
Bile
E.
Saliva
【单选题】Quantitatively, the most important form of carbon dioxide transport it?（ ）
A.
CO2 combined with plasma proteins
B.
HCO3- produced in erythrocyte
C.
CO2 dissolved in the erythrocyte
D.
HCO3- produced in plasma
E.
CO2 dissolved in plasma
【单选题】Which antigen is on the erythrocyte membrane of type AB blood （ ）
A.
A antigen
B.
Rh antigen
C.
D antigen
D.
A and B antigens
E.
B antigen
【单选题】The wrong description about the role of the sympathetic nerve on the heart is that（ ）
A.
Beta receptors on the membrane of the heart muscle
B.
The transmitter released from the end is norepinephrine
C.
Increase ventricular end-diastolic volume
D.
Increase cardiac output
E.
It can accelerate heart rate and strengthen myocardial contractility
【多选题】Which of the following organ activities is involved in maintaining homeostasis in the internal environment（ ）
A.
The digestion and absorption of the digestive system
B.
Excretory function of the kidney
C.
Contraction of skeletal muscle
D.
Respiration
E.
Blood circulation