说明：这三种被动形式主要用来作后置定语，所以我们在本节讨论。但也可作状语或补足语。
a.The question being discussed is very important.
b.The house being built will be our library upon its completion.
c.Are you going to attend the meeting to be held next month ?
d.Did you attend the meeting held last month in Shanghai?
e.For any adhesive to make a really strong bond, the surfaces to be glued must be absolutely clean and free from moisture or grease.
对于任何黏合剂，要想粘得牢固的话，则被粘的表面必须绝对清洁且不能潮湿和有油性物质。
f.More than 300 local college students attended the torch relay to show their support for the 21st Universiade, to be held in Beijing between August 22nd and September 1st.
g.A stranger shoved a gun_________in a paper against his back and muttered, "I'm going in with you. This is a stickup（抢劫）!”
A. concealed
B. being concealed
C. to be concealed
D. concealing
正确答案：A。
h.A tiger can't be tamed unless_________very young.
A. being caught
B. caught
C. it being caught
D. it's being caught
正确答案：B。
i.The project_________by the end of 2035, will expand the city's telephone network to cover 1,000,000 users.
A. accomplished
B. being accomplished
C. to be accomplished
D. having been accomplished
正确答案：C。
j.If I correct someone, I will do it with as much good humor and self-restraint as if I were the one _________.
A. to correct
B. correcting
C. having corrected
D. being corrected
正确答案：D。