Scientists study ________ human brains work to make computers.(2012·四川，17)

A．when B．how

C．that? D．whether

I’m afraid he’s more of a talker than a doer，which is ________ he never finishes anything.????????????? ????????????? ????????????? ????????????? ????????????? ????????????? ????????????? ????????????? ????????????? ????????????? (2011·山东，26)

A．that? B．when

C．where? D．why

________ caused the accident is still a complete mystery.

A．What? B．That C．How? D．Where

I just wonder ________ that makes him so excited.

A．why it does? B．what he does

C．how it is? D．what it is

Water，which seems so simple and common，is ________ makes life possible.

A．what? B．that

C．which? D．how

I’d like to work with ________ is honest and easy to get on with.

A．who? B．whoever

C．whomever? D．no matter who

When you are reading，make a note of ________ you think is of great importance.

A．which? B．that

C．what D．when

Mr.Smith asked the boy a question________he could go to the concert with him.

A．whether? B．that

C．what? D．if

A warm thought suddenly came to me ________ I might use the pocket money to buy some flowers for my mother’s birthday.

A．if? B．when

C．that? D．which

There is much chance ________ Bill will recover from his injury in time for the race.

A．that? B．which

C．until? D．if