[单选题,A1型题]

The purpose of the ashing step in graphite-furnace atomic-absorption spec-troscopy is to（）

A . Vaporize metal atoms to be analyzed

B . Cause the metal species to form carbides which are more volatile

C . Convert the graphite furnace to ash to avoid carbide formation

D . Burn off organic species that would interfere with the elemental analysis

参考答案与解析：

相关试题

Windows provides a user£­friendly graphi

[单选题]Windows provides a user-friendly graphical( )including pop—up menus，scroll bars，dialogue boxes，icons and etc.A．displayB．surfaceC．interfaceD．help

  • 查看答案

    • Windows provides a user£­friendly graphi

    [单选题]Windows provides a user-friendly graphical ______ including pop-up menus，scroll bars， dialogue boxes，icons and etc．A．displayB．surfaceC．interfaceD．help

  • 查看答案

    • The purpose of the writing is to ______.

    [单选题]The purpose of the writing is to ______.A． promote scenic spots in Canada B. advertise for the sports in BanffC． introduce tourist activities in Banff D. describe breathtaking views in Banff

  • 查看答案

    • The purpose of the memo is to

    [单选题]The purpose of the memo is toA．attract students’interest in the programmeB．require the parents to select a sport for their chinldC．help the staff explain the programme to the parentsD．remind teachers and lifeguards to be present on time

  • 查看答案

    • ( )The purpose of the three ads is to __

    [单选题]（ ）The purpose of the three ads is to __________.A．sell these books to the childrenB．help children learn EnglishC．help children learn about natureD．use a dictionary to pronounce correctly

  • 查看答案

    • The main purpose of the text is to _____

    [单选题]The main purpose of the text is to _______.A． describe children’s thinkingB．answer some questions children haveC．stress the importance of communicationD．advise parents to encourage their children

  • 查看答案

    • The purpose of the program is to provide

    [单选题]The purpose of the program is to provide training for employees so that they can work ______.A． lateB． laterC． latelyD． latest

  • 查看答案

    • The purpose of the requirements definiti

    [单选题]The purpose of the requirements definition phase is to produce a clear, complete, consistent, and testable(71 )of the technical requirements for the software product.During the requirements definition phase, the requirements definition team uses an i

  • 查看答案

    • The main purpose of the text is to _____

    [单选题]The main purpose of the text is to _______.A． describe children’s thinkingB．answer some questions children haveC．stress the importance of communicationD．advise parents to encourage their children

  • 查看答案

    • The purpose of the flywheel of a diesel

    [单选题]The purpose of the flywheel of a diesel engine is to （）.A . counterbalance the crank throws on the crankshaftB . keep the engine running smoothly between power strokeC . provide a belt-driving surface for the operation of auxiliary machineryD . preve

  • 查看答案