___ all drugs have the potential to be both beneficial and harmful should not be ignored when using them.
A.How long   
B.However    
C.Whether     
D.The fact that

In Greek legend, the people of Thebes offered not only the throne but also the hand of Queen Jocasta to ___ could answer the riddle posed by a monster which was terrorizing the people.
A.whichever
B.whoever
C.wherever   
D.whomever

His Collected Essays continues to reveal ___ George Orwell understood the basic conflicts of the modern world.
A.how well    
B.so well
C.if ever
D.just as

He adores his little granddaughter so he’ll do ___ she wants him to do.
A.all of them
B.however     
C.most of all
D.whatever

The Parents’ Committee still can’t decide ___ the construction of a new playground really is necessary.
A.despite
B.whether     
C.in case
D.so as

Do you know ___ agent Kate and Richard went to Vietnam with because I’m thinking of booking a trip to Hanoi myself?
A.which
B.who
C.where
D.when

My watch is slow and_________is my brother's.
A.either
B.too
C.so
D.neither

The recent report on ___ areas will be affected the most during an earthquake explains ___ the housing prices have dropped so drastically in that area: it was on the top of the list.
A.how long - that
B.which - why
C.when - what        
D.what - how

It has been confirmed recently  ___ using mobile phone can cause brain damage.
A.if
B.that
C.what
D.when

___ thinner she’s been looking ever since she joined that new gym! I may have to start going myself.
A.How much
B.How long
C.What
D.What on earth