I have often seen him（)upon the moon and stars for hours. Why do you think he is doing that？

听力原文：W: Hi, Tom.

M: Kate, I haven't seen you for weeks. Where have you been？

W: In Florida.

M: What？ Vacationing while the rest of us have been studying on the campus in the February cold？

W: Not exactly. I spent most of my time underwater.

M: I don't understand.

W: I was on a special field trip. I went with my marine biology class.

M: So you went scuba diving. What were you looking for, sunken treasure？

W: You might say so. The sea is full of treasures. All kinds of strange, fascinating organisms. Our class concentrated on studying plankton.

M: I thought they were too small to be seen.

W: That's a common misconception. The plankton covers a wide variety of freely floating plants and animals. From one-celled organisms to large ones, such as the common jelly fish.

M: Jelly-fish may be large enough to be seen. But they are transparent, aren't they？

W: Yes, most floating plants and animals have transparent tissues. It makes them practically invisible to their enemies.

M: But not invisible to your biology class, I hope.

W: By concentrating, I was able to see the outlines of lots of different plants and animals, In fact, our professor even took photo of some small oceanic snails.

M: How would the snails show up in the photo if they are transparent？

W: We painted them with a harmless green dye. Since particles of the dye stuck to the tissues, the snails appeared in a green outline in the photos.

M: That sounds like an interesting trip.

W: It really was.

M: But I think if I had been there, I'd much rather have spent my time just swimming and lying in the sun.

(20)

A．Sightseeing.

B．Lying on the beach.

C．Taking photos of the beaches.

D．Scuba diving.

e papers and books.Not only 22 never to be cleaned out, but also I do not think it is ever aired, for at no time have I seen any of the windows open.Often I have 23 James that he should open one, but each time he answered, “Not just now, Henry, later”.Luckily I do not have to go there very often nor do I stay there longer than I have to.Strangely enough, James is quite tidy outside his office.Only once have I seen him with a dirty 24 , for example.Nor is he careless about things like invitations.At no time 25 been known to forget a party, and no sooner does he receive an invitation 26 he answers it.Unfortunately, his office is quite differently run.Perhaps he does not like such a work.In his garden in the evenings and 27 , James is happy as soon as he gets home from the office.He begins to work in the garden.Always he seems to have some work to do there, and nowhere in his garden is there a curlier which is not tidy and well looked 28 .Seldom have I seen prettier flowers, or healthier vegetables, or smoother, greener grass than in James garden.Really.I think he ought 29 a farmer, so good is he 30 such work.

21.A.have I

B.do I

C.I have

D.I do

22.A.does it seem

B.it does seem

C.it seems

D.is it seem

23.A.hinted

B.suggested

C.asked

D.mentioned

24.A.dog

B.collar

C.caller

D.dollar

25.A.will he

B.he will

C.has he

D.he has

26.A.than

B.as

C.and

D.when

27.A.in week-ends

B.in week-end

C.by week-ends

D.at week-ends

28.A.about

B.after

C.at

D.for

29.A.work as

B.to go

C.to have been

D.become

30.A.for

B.at

C.in

D.with

_____ advertisements showing happy, balanced families.

(A) are often seeing (C) will often see

(B) often see (D) have often seen

ng carbon footprints.

A. will often see

B. often see

C. are often seeing

D. have often seen

e paper, magazine, or commercial on television.

A、by means of

B、at the cost of

C、in response to

D、in charge of

seen in Disneyland.

A.cushions

B.skeletons

C.ornaments

D.costumes

A.hundred of

B.hundreds

C.hundreds of

D.hundred

Waiters and waitresses often introduce _____: “Hi! I’m Don (or Debbie).”

A: them

B: they

C: themselves

D: theirs

A.learn from

B.hear from

C.hear of

D.listen to

Turn on the television or open a magazine and you _____ advertisements showing happy, balanced families.

(A) are often seeing (C) will often see

(B) often see (D) have often seen