________ he met with the difficulty did he realize the importance of our help．

A．Even though

B．Never until

C．Only before

D．Ever since

It was not until ________ that ________ to prepare his lessons．

A．did his father come in; the boy began

B．his father came in; the boy began

C．did his father come in; did the boy began

D．his father came in; did the boy begin

－Is the flower beautiful?

－Yes, at ________ it's ________ the one I bought yesterday．

A．least; as bad as

B．least; no better than

C．least; not better than

D．least; no worse than

As we know, Canada is ________ country in the world．

A．a second larger

B．the second largest

C．the second large

D．the second larger

How beautifully she sings! I've never heard ________．

A．the better voice

B．a good voice

C．the best voice

D．a better voice

Greenland, ________ island in the world, covers over two million square kilometres．

A．it is the largest

B．that is the largest

C．is the largest

D．the largest

He ________ his spare time helping his little brother learn English．

A．costs

B．takes

C．spends

D．spare

Some passengers complain that it usually ________ so long to fill in travel insurance documents．

A．costs

B．takes

C．spends

D．spares

According to a recent U．S．survey, children spent up to 25 hours a week ________ TV．

A．to watch

B．to watching

C．watching

D．watch

Fortunately ________ him he grasped a big piece of wood, and the water ________ him to the bank of the river．

A．for; floated

B．to; flowed

C．for; flew

D．to; floated