_______ from the moon, our earth, with water _______seventy

应该选A 还是B咧,为什么啊
（ ）from the moon,our earth,with water( )seventy percent of its surface ,appear a blue ball
A.seen；covered B.seening；covered

作文。

请以“Our earth”为题写一篇不少于50词的作文。 _______________________________________________________________________________________ _______________________________________________________________________________________ _______________________________________________________________________________________ _______________________________________________________________________________________ _______________________________________________________________________________________ _______________________________________________________________________________________

Seen from the moon,our earth ,with water c_______ eventy of its surface ,appears as a blue ball.
横线处填什么,并说明原因

题号:1 题型:单选题
___ from space,our earth,with water covering 70 percent of its surface,looks like a blue planet.
选项:
a、Seen
b、Seeing
c、Having seen
d、To see
题号:2
You should make ___ your house or flat is secure.
选项:
a、sure
b、certain
c、understanding
d、knowledge
题号:3
They carry ___ with their work in spite of the extremely difficult conditions.
选项:
a、out
b、over
c、on
d、back
题号:4
The committee proposed that more emphasis should be laid ___ developing practical skills in students.
选项:
a、onto
b、to
c、on
d、over
题号:5
How the fire in the dance hall started ___ a mystery.
选项:
a、to remain
b、remains
c、remain
d、is remaining
题号:6
I believe you have ___ some important points in the report.
选项:
a、left alone
b、left behind
c、left off
d、left out
题号:7
Canned foods are ___ with housewives because it takes so little time to cook them.
选项:
a、popular
b、welcome
c、desirable
d、usual
题号:8
She was ___ the top prize in the competition.
选项:
a、awarded
b、rewarded
c、received
d、accepted
题号:9
To speak English well,___.
选项:
a、much practice is needed
b、one needs much practice
c、much practice is needed by one
d、one is needed much practice
题号:10
She can speak French and German,to ___ nothing of English.
选项:
a、say
b、speak
c、talk
d、tell
题号:11
I prefer classic music ___ pop music.
选项:
a、than
b、on
c、with
d、to
题号:12
The hall was almost empty.There were ___ people in it.
选项:
a、little
b、a little
c、few
d、a few
题号:13
I want to update my English ability,but I have no idea what kind of material ___.
选项:
a、to listen to
b、listening to
c、for listening
d、to listen
题号:14
I did not buy the same book ___.
选项:
a、what he bought
b、that he bought
c、as he bought
d、which he bought
题号:15
It is not that I do not like plays.The reason why I did not go to the theater last night was that I could not ___ the time.
选项:
a、offer
b、leave
c、afford
d、manage
题号:16
As a senior,please give me ___ advice you can give on this issue.
选项:
a、that
b、what
c、which
d、whatever
题号:17
We failed in our ___ to climb the mountain.
选项:
a、trial
b、contempt
c、desire
d、attempt
题号:18
The passengers desire that the airline ___ them immediately of any change in flight time.
选项:
a、inform
b、informs
c、informed
d、has informed
题号:19
The teacher ___,the children in the classroom burst into talking instantly.
选项:
a、having left
b、left
c、leaving
d、to leave
题号:20
A new driver can not be ___ careful in driving a car.
选项:
a、very
b、quite
c、rather
d、too

高一英语.
-------our earth,or else will be no longer fit for us to live on.A.protected B.To protect C.protecting D.protect
这题应选D,可是不是主动用ing,被动用ed吗?这里怎么用原型,是祈使句吗?怎样才区别开什么时候用ed,什么时候用ing,什么时候用原型呢?