问题 单项选择题

有关动作电位的说法中,

不当

的是

A.动作电位或峰电位的产生是细胞兴奋的标志
B.只要刺激达到足够的强度,再增加刺激强度能使动作电位的幅度增大
C.动作电位不是只出现在受刺激的局部
D.动作电位传播的范围和距离不因初刺激的强弱而有所不同,直至整个细胞的膜都依次产生同样的动作电位
E.动作电位是先出现膜的快速去极化再出现复极化

答案

参考答案:B

解析: 动作电位产生的特点是,只要刺激达到足够的强度,再增加刺激强度并不能使动作电位的幅度增大,始终保持某种固有的大小和波形。

单项选择题
单项选择题

(B)

When first entered, Vanak Restaurant does not look like much of a restaurant, but once the pleasant smells of kabob(烤肉串)hit the senses, you are incapable of calling it anything less.

Owned by a local couple, this Persian restaurant has an inviting, homelike atmosphere that many restaurants lack.

The space is small with only a few dining tables and nearly no decoration, but the environment is truly charming.

Lying in a hardly noticeable steed corner, the restaurant still attracts all customers, especially those experienced in the delights of Middle Easter cooking.

A common sight is that of old Persian men sitting in the corner talking loudly about world topics, watching news events on TV, drinking a black tea known as Persian chai, and reading local Persian newspapers all the while trying to finish off their plates piled with food.

The variety of food at the restaurant is limited, but the amount of each dish is fairly large. Most of the meals can serve two people and are under $10, so not only is it affordable but practical as well.

The food especially appeals to health-conscious eaters because each dish is very healthy, made with limited fat and oil and served straight off the grill.

The main dish that the restaurant is popular for its kabobs, which are different styles of grilled meat.

One delicious and extremely healthy dish is the Joojeh Kabob, which is made of grilled chicken pieces served with either rice or bread. Another great kabob is the Chelo Kabob, a kabob consisting of grilled beef.

Although the restaurant is small, the atmosphere and the food is delicious. It is a place that should not be overlooked.

When first entering the restaurant, one can find that it()

A. is splendidly decorated

B. has pleasant smells of kabobs

C. is crowded with dining tables

D. looks like a common restaurant