细菌可经下列哪些途径进入肝脏引起细菌性干脓肿 A．胆道 B．肝动脉 C．门静脉 D．

把A-D四个句子填入文中空缺处(1-4)，使短文内容完整，然后完成第5题。

      One of the first ways to communicate over long distances was by a messenger, 1_____. At that time

messen- gers had to spend a long time doing the job and sometimes they forgot the reply. The invention of

writing helped them a lot. They are called postmen now.

      People around the world developed many different ways to send messages: blowing into seashells, using

smoke from fires, even throwing bottles with messages in them into the sea. 2_____.  Soldiers used to write

messages and fix them to the leg of the pigeon. The pigeon then flew back home with the information. One

pigeon flew 4500 kilometers from the United States to Britain in 12 days-a speed of 375 kilometers a day!

3_____. George Lesage made the first electric telegraph in 1774. And Alexander Graham Bell invented the

telephone in 1876. 4_____. Today we also have mobile phones, faxes, communication satellites, e-mails and

the Internet to help us exchange information quickly around the world.

A. In the 1920s, scientists invented radio telephones

B. One successful way was to use pigeons, a kind of bird

C. someone who took messages from place to place

D. The first modem ways of communicating were by telegraph and telephone

5. Which is the best title of the passage? 

A. The Best Communicating Way.

B.  Useful Pigeons.

C.  Long-Distance Communication.

D.  The Popular Internet

若x=1是一元二次方程x²+3x+m=0的一个根，则m=______．

右肩关节活动受限1年多，体检发现右手上抬不能，后展受限，行右肩关节摄片如图示，最可能的诊断是（）

A.正常右肩关节

B.右肱骨骨质疏松

C.右肩关节周围炎

D.右肩关节滑囊炎

E.右肩关节结核

按信息传、受的范围大小，传播学分为的研究层次是（）

A.自我传播

B.人际传播

C.群体传播

D.组织传播

E.大众传播

液空液面正常，主冷液面下降，为保证制氧机正常运行，应该（）。

A.开大液空节流阀

B.增加膨胀量

C.减少氧产量

D.减少氮产量