After a year, doctors diagnosed him with a disease so rare ________ it affects just one in 8 million children.
| A．after | B．that | C．as | D．since |
Scientists think that the continents ____ always where they ___today.
| A．aren't; are | B．aren't; were | C．weren't; are | D．weren't; were |
--- Would you tell me ___ you want your tea, with sugar or milk?
--- Sugar, please.
| A．whether | B．where | C．what | D．how |
Leaves are found on all kinds of trees, but they differ greatly __ size and shape.
| A．on | B．from | C．by | D．in |
He began to take political science_____ only when he left school.
| A．strictly | B．truly | C．carefully | D．seriously |
I can't say which wine is best-it's a (n) ___ of personal taste.
| A．affair | B．event | C．matter | D．variety |