----No one is so ____ about his joy as Doctor Li.
----You are right. He devotes all his time and energies to his cause.
| A．mad | B．wild | C．serious | D．crazy |
When you are reading，make a note of ________ you think is of great importance.
| A．which | B．that |
| C．what | D．when |
I’d like to work with ________ is honest and easy to get on with.
| A．who | B．whoever |
| C．whomever | D．no matter who |
Water，which seems so simple and common，is ________ makes life possible.
| A．what | B．that |
| C．which | D．how |
I just wonder ________ that makes him so excited.
| A．why it does | B．what he does |
| C．how it is | D．what it is |
________ caused the accident is still a complete mystery.
| A．What | B．That | C．How | D．Where |