问题 单项选择题 A3/A4型题

某食堂6月份供应蛋炒饭,引起近百人食物中毒。发病潜伏期约8小时,以腹痛、腹泻为主要症状,不发热,病程为16~36小时,预后良好。经卫生学调查发现,蛋炒饭所用的米饭是前一天的剩饭。其中毒机制为()

A.细菌活菌

B.细菌内毒素

C.细菌肠毒素

D.细菌活菌加内毒素

E.细菌活菌加肠毒素

答案

参考答案:E

阅读理解

(二)   66  Scientists and experts have proved the uniqueness of finger-prints and discovered that no exactly similar pattern is passed on from parents to children, though nobody knows why this is the case.

The ridge (隆起) structure on a person's fingers does not change with growth and is not affected by surface injuries. Burns, cuts and other damage to the outer part of the skin will be replaced in time by new one, which bears a reproduction of the original pattern.  67   Some criminals make use of this fact to remove their own finger-prints but this is a dangerous and rare step to take.

Finger-prints can be made very easily with printer's ink. They can by be recorded easily.  68  Because of the simplicity and economy of this system, finger-prints have often been used as a method of solving criminal case. A suspected man may deny a charge but this may be in vain. 69  . When a suspect leaves finger-prints behind at the scene of a crime, they are difficult to detect with the naked eye.   70  Some of the marks found are incomplete but identification is possible if a print of a quarter of an inch square can be obtained.

A.Special techniques are used to "develop" them.

B.A fingerprint is an impression of the friction ridges of all part of the finger.

C.It is only when the inner skin is injured that the arrangement will be destroyed.

D.With special methods, identification can be achieved successfully within a short time.E. A latent print is the chance reproduction of the friction ridges deposited on the surface of an item.

F. His finger-prints can prove who he is even if his appearance has been changed by age or accident.

G. Every human being has a unique arrangement of the skin on his fingers and this arrangement is unchangeable.

单项选择题