Scientists in some countries have done a lot of work to _____ the moon.
A. cover B. search C. explode D. explore
She does not know _____ the situation, for she is too inexperienced.
A. how to deal with B. what to deal with
C. how to deal with it D. what to do with it
I know these flowers are not natural, but the _____ ones look more beautiful and can last long.
A. fresh B. new C. trueD. artificial
Cattle’s two ____ help them to digest food and their fur to keep them warm.
A stomaches B heart C stomachs D hearts
Great attention must be paid ____ welfare, especially in the poor area.
A. develop B. to develop C. to developing D. developing
________they visited the Science Museum，they showed great interest in everything they saw.
A．The first time B．For the first time C．At first D．At the first time
