预调锥体后还需要对锥体进行检查，可采用（）方法检查。 A.电子检查 B.拍照检查 C

男性患者，70岁。近2年出现消瘦，进行性吞咽困难，胸骨后疼痛症状，遂来院就诊。

进展期食管癌患者，进行内镜下介入治疗的方法有（）。

A.内镜下黏膜切除术

B.内镜下单纯食管扩张术

C.内镜下癌肿套扎术

D.内镜下癌肿消融术

E.食管内支架放置术

F.内镜下血管硬化治疗

G.内镜下局部药物注射

目前人类已发现几千万种物质，对物质进行分类，有利于我们的学习．下列关于物质的类别中，不正确的是（括号内为类别）（　　）

A．H₂O（氧化物）

B．H₂SO₄（含氧酸）

C．CH₃COOH（混合物）

D．I₂的CCl₄溶液（混合物）

The biggest danger facing airlines nowadays may not be a terrorist with a gun, but the man with portable computer in business class. In the last 16 years, pilots have reported well  over 100 incidents that could have been caused by electromagnetic interference  (电磁干扰).  The source of this interference remains not proved, but increasingly, experts are pointing the  blame at portable electronic devices such as portable computers, radio and cassette players  and mobile telephones.

RTC.A. an organization which advises the aviation  (航空 )industry, has suggested that all  airlines ban such devices from being used during "critical" stages of flight  particularly take-  off and landing. Some experts have gone further, calling for a total ban during all flights .Cur- rently , rules on using these devices are left up to individual airlines. And although some air- lines prevent passengers from using such equipment during take-off and landing, most are un- willing to carry out a total ban, given that many passengers want to work during flight.

The difficulty is predicting how electromagnetic fields might affect an aircraft's computers. Experts know that portable devices send out radiation which affects those wavelengths which aircraft use for navigation and communication. But, because they have not been able to reproduce these effects in a laboratory. they have no way of knowing whether the interference might be. dangerous or not.

The fact that aircraft may be fragile to interference raises the risk that terrorists may use radio systems in order to damage navigation equipment. As worrying, though, is the passenger who can 't hear the instructions to turn off his radio because the music's too loud.

小题1:What is said about the over 100 aircraft incidents in the past 16 years?

A．They may have been caused by the damage to-the radio systems.

B．They may have taken place during take-off and landing.

C．They were proved to have been caused by the passengers portable computers.

D．They were suspected to have resulted from electromagnetic interference.小题2:Why is it difficult to predict the possible effects of electromagnetic fields on an airplane 's computers?

A．Because it is extremely dangerous to conduct such research on an airplane.

B．Because it remains a mystery what wavelengths are liable to be interfered with.

C．Because research scientists have not been able to produce the same effects in labs.

D．Because experts lack adequate equipment to do such research.小题3:Few airlines want to perform a total ban on their passengers using electronic devices because_______

A．they don't believe there is such a danger as radio interference

B．the harmful effect of electromagnetic interference is yet to be proved

C．most passengers refused to take a plane ,which bans the use of radio and cassette players

D．they have other effective safety measures to fall back on小题4:The passage is mainly about_________.

A．a new rule for all airlines

B．the disadvantages of electronic devices

C．a possible cause of aircraft incidents

D．effective safety measures for air flight

在DNA变性过程中，总是G-C对丰富区先融解分开。 ( )

高技术产业化的过程