问题 选择题

为了除去粗盐中的Ca2+、Mg2+、SO42-及泥沙,可将粗盐溶于水,然后进行以下五项操作:①过滤;②加过量NaOH溶液;③加适量稀盐酸;④加过量Na2CO3溶液;⑤加过量BaCl2溶液,正确的是(  )

A.①④②⑤③

B.④①②⑤③

C.②⑤④①③

D.②④⑤①③

答案

答案:C

阅读理解

There was a pilot(飞行员) and four people in a small plane. Suddenly there was something wrong with the machine while it was flying in the air. The plane began to fall down. The pilot told the people there were only four parachutes(降落伞). They all became worried and started to make excuses.

The next person said, “I must have a parachute. I am a very clever person. I have to attend an important match. I know I will win the game because I’ll be the cleverest person there.” He picked up a pack and jumped out.

Two men were left---an old businessman and a young mountain climber. At this time the plane was going down fast. The businessman said, “ Young man, I am old but you are still young. You take the last parachute.” The young mountain climber smiled. “Don’t worry,” He said. “ We can both jump out because there are still two parachutes. Just now the clever man jumped out with my backpack.”

小题1:All the people became worried because_________.

A.they couldn’t find the parachutes

B.they saw the pilot jump out first

C.they were afraid and they knew there were not enough parachutes for each person.

D.There was too much smoke and they couldn’t jump out from the plane.小题2:The clever man jumped out with_________.

A.a parachute

B.nothing

C.the backpack of the climber’s

D.two parachutes小题3:All the people thought of themselves except____________.

A.the pilot

B.the clever man

C.the doctor

D.the businessman小题4:From the story we know__________ would be dead.

A.the clever man

B.the businessman

C.the pilot

D.the doctor小题5:From the passage we know_________ was the first to jump off the plane.

A.the pilot

B.the mountain climber

C.the businessman

D.the doctor

问答题 简答题