[单项选择]"I don't know what they are but I' ve got an open mind on them" (in the second paragraph) probably means that ______.
A. he believes the UFO comes from outer space
B. he disbelieves the UFO comes from outer space
C. he neither believes nor disbelieves that the UFO comes from outer space
D. he agreed with most of the people

[单项选择]"I don't know what they are but I' ve got an open mind on them" (in the second paragraph) probably means that ______.


A. he believes the UFO comes from outer space
B. he disbelieves the UFO comes from outer space
C. he neither believes nor disbelieves that the UFO comes from outer space
D. he agreed with most of the people

[单项选择]I don't know what makes Christina so attractive to young men.


A. charming
B. special
C. different
D. beautiful

[单项选择]I've worked with children before, so I know what ______ in my new job.
A. expected
B. to expect
C. to be expecting
D. expects

[单项选择]I don't know what his interests are, because we talked ______ about work when we met.
A. main
B. mainly
C. major
D. majorly

[单项选择]I don't know what illness he suffered from, but I do remember he mentioned（　）in hospital last year.
A. to have been
B. to be
C. having been
D. being

[单项选择]

What we don’t know or refuse to recognize is that modern man has been altering his total environment so swiftly and suddenly that the whole "great chain of life" on this planet is in danger.
All of us live on a tiny spaceship carrying with it its own limited resources for survival.What we have now is all we will ever have to keep us alive.
But man has been harming this system. He cannot help it. Everything we do alters our environment: the ways we grow food and build shelter and create what we call "culture" and "civilization".
World population is growing at such a rate that by the year 2050 nearly seven billion people will live on the earth.Industrialization has added its own burden to the population pressure. The more we produce and consume, the more waste products we discharge into the air and water and land around us, where they do not disappear, but last forever in one form or another. Great progress i
A. great progress
B. agriculture
C. our soil
D. productivity

[单项选择]If you know what the trouble is, why don't you help them to ______ the situation
A. simplify
B. modify
C. verify
D. rectify

[单项选择]When you don't know what to do next, never give up, just ______. working out your problem.