What’s really needed, according to most researchers in this field, ________ a "killer" application particularly suited for the way DNA computing solves problems．

A．being                     B．are                         C．is                          D．was

--- What time do we have to be at the gate?

--- __________ passengers are already boarding．

A．Hurriedly         B．Soon                      C．Immediately           D．Since

Microsoft's next major operating system, Windows Vista, looks ________from today's Windows．

A．different                 B．differently              C．difference              D．differences

The flowers _________ sweet in the botanical garden attract the visitors to the beauty of nature．

A．smell                      B．smelling                  C．smelt                      D．to be smelt

--- I think I’ll give Bob a ring．

--- You _______．You haven’t been in touch with him for ages．

A．will                        B．May                       C．have to                   D．should

--- This store has such high prices．

--- I agree．Never again __________ here．

A．I will shop              B．I do shop                C．will I shop                   D．shop I do

_______ no need to worry about his safety, because he is always careful．

A．What’s                  B．It’s                        C．There’s                 D．Which’s

On the contrary, I think it is John, _________ you, _________ to blame．

A．more than; are               B．less than; who are   C．rather than; that is   D．rather than; is

I will appreciate it very much ________ you could change your plan a little bit to make it more workable．

A．if                           B．that                        C．whether                  D．unless

Two friends visited the zoo together．The zoo was very large and it was  1  to go everywhere．They had to decide where to go and which animals to visit as their time was  2  So both of them agreed not to 3  after choosing a  4  at every fork（岔路口）．

A road sign at the first fork  5 one way to the lion area and the other to the tiger hill．They decided on the former after a  6  discussion because lions were “the king of the grassland”．The second showed a division going separately to the panda and peacock．They  7  panda as it was the nation’s treasure and went its way．

  8  they made choices all along the way and each choice meant  9  what they couldn’t help regretting．But they had to make it, and  10  , for it brooked（容忍）no delay．If they hesitated（犹豫不决） they would miss  11  ．Only  12 decision could offer more chances for sightseeing and  13  possible regret．

Life is  14 like this----- choices often occur that one has to make, for example, between two  15  jobs, two fascinating wooers（追求者）．To get one you  16  give up the other-you can get half of it．If you 17  weighing the pros and cons and calculating gains and losses, you will most likely  18  empty-handedness．Don’t be sad about it． 19  you have got half of the desirable things in life ----something that is  20 to come by．

1．A．easy                        B．difficult                  C．impossible              D．possible

2．A．enough                     B．limited                    C．tight                       D．plentiful

3．A．return                      B．continue                 C．go                         D．stop

4．A．sign                         B．branch                   C．crossing                 D．highway

5．A．showed                   B．pointed                   C．intended                 D．made

6．A．brief                        B．long                       C．no                         D．heated

7．A．hoped                      B．wanted                   C．favored                   D．got

8．A．Happily                    B．Thus                      C．Then                     D．Finally

9．A．winning                   B．taking                    C．picking up              D．giving up

10．A．slowly                   B．immediately            C．timely                    D．easily

11．A．less                       B．more                      C．most                      D．least

12．A．high                B．slow                      C．short                     D．rapid

13．A．increase                 B．cause                     C．reduce                   D．raise

14．A．just exactly             B．more or less           C．hardly                    D．most

15．A．unwanted               B．different                 C．bad                        D．desirable

16．A．ought to                 B．may                       C．must                      D．have to

17．A．spend time             B．kill time                  C．have a hard time     D．hope for

18．A．start with                      B．get up                    C．succeed in              D．end up in

19．A．By no means          B．Not in the least        C．At most                 D．At least

20．A．stupid                    B．delighted                C．hard                     D．supported