We were heartedly arguing about the financial matter, （）the telephone rang unexpectedly.

A:while      B:as       C:C, when     D:as soon as

A number of persons have expressed concern about possible health dangers to workers who use devices called video-display terminals (终端) or VDTs. These are the devices used to show computer information. Some reports link VDTs to health disorders including eye problems and muscle problems. Even the health of the pregnant women and their unborn babies is said to be endangered. Video-display terminals produce low levels of the electromagnetic radiation(电磁辐射). Experts say most modern VDTs have been designed to limit the dangers from such radiation. However, study shows that even low levels of electromagnetic radiations can affect the growth of the cells. As a result, some doctors advise women to stop working with VDTs while they are pregnant. One study found women who work with VDTs in early pregnancy are more likely than others to have their pregnancy end unexpectedly. Researchers said that this does not necessarily mean that VDTs themselves cause problems. Some experts said the findings show working conditions, not the machines, cause the problems. Law makers in m6re than American states have proposed bills to control working conditions for VDT operators.

A:Study shows working with VDTs would cause miscarries (流产）. B:Study shows even low levels of radiation is harmful. C:Study shows working conditions rather than VDTs have the pregnancy ended unexpectedly. D:Study shows stopping working with VDTs is the best way to protect women's healt

We were arguing about the financial matter, ______ the telephone rang unexpectedly.

A:as B:while C:when D:as soon as

We were heartedly arguing about the financial matter, ______the telephone rang unexpectedly.
A. while B. as C, when D. as soon as

A:C, when B:as soon as C:as D:We were heartedly arguing about the financial matter, ______the telephone rang unexpectedly. E:while

We were heartedly arguing about the financial matter, （）the telephone rang unexpectedly.

A:while      B:as       C:C, when    D:as soon as

I unexpectedly（　） him on the street yesterday evening.

A:ran after B:ran through C:ran to D:ran into

His friend unexpectedly dropped in.

A:visited B:stepped in C:dropped off D:met