对肌肉僵直和运动困难疗效较好的药物是

A．左旋多巴
B．利舍平
C．苯海索
D．维生素B₆
E．金刚烷胺

Like many other aspects of the computer age, Yahoo began as an idea, (1) into a hobby and lately has (2) into a full-time passion. The two developers of Yahoo, David Filo and Jerry Yang, Ph. D candidates (3) Electrical Engineering at Stanford University, started their guide in April 1994 as a way to keep (4) of their personal interest on the Internet. Before long they (5) that their homebrewed lists were becoming too long and (6) . Gradually they began to spend more and more time on Yahoo.

During 1994, they (7) yahoo into a customized database designed to (8) the needs of the thousands of users (9) began to use the service through the closely (10) Internet community. They developed customized software to help them (11) locate, identify and edit material (12) on the Internet. The name Yahoo is (13) to stand for "Yet Another Hierarchical Officious Orale", but Filo and Yang insist they selected the (14) because they considered themselves yahoos. Yahoo itself first (15) on Yang’s workstation, "akebono", while the search engine was (16) on Filo’s computer, "Konishiki".

In early 1995 Marc Andersen, co-founder of Netscape Communication in Mountain View, California, invited Filo and Yang to move their files (17) to larger computers (18) at Netscape. As a result Stanford’s computer network returned to (19) , and both parties benefited. Today, Yahoo (20) organized information on tens of thousands of computers linked to the web.

6（）

A.unwieldy

B.tough

C.tamable

D.invaluable