问题 选择题

做屈肘动作时,没有参与的人体结构是(  )

A.肱二头肌

B.肱三头肌

C.肘关节

D.指关节

答案

骨的位置的变化产生运动,但是骨本身是不能运动的.骨的运动要靠骨骼肌的牵拉.骨骼肌包括中间较粗的肌腹和两端较细的肌腱(乳白色),同一块骨骼肌的两端肌腱绕过关节连在不同的骨上.骨骼肌有受刺激而收缩的特性,当骨骼肌受神经传来的刺激收缩时,就会牵动骨绕着关节活动,于是躯体就会产生运动.但骨骼肌只能收缩牵拉骨而不能将骨推开,因此与骨相连的肌肉总是由两组肌肉相互配合活动的.例如,屈肘动作和伸肘动作的产生.屈肘时,肱二头肌收缩,肱三头肌舒张,伸肘时,肱三头肌收缩,肱二头肌舒张. 在运动中,神经系统起调节作用,骨起杠杆的作用,关节起支点作用,骨骼肌起动力作用.可见,人体完成一个运动都要有神经系统的调节,有骨、骨骼肌、关节的共同参与,多组肌肉的协调作用,才能完成.

故选:D

选择题
阅读理解

Alaska Inside Passage Craises

Most cruises(游船) are seven nights long and typically begin an4 end in either Vancouver or Seattle.This "roundtrip" travel plan makes this a very popular cruise vacation because of the convenient flight schedules and affordable roundtrip airline tickets into and out of Vancouver and.Seattle.Longer 10-night and 11-night Inside Passage Cruises are available from California.Depending on your ship and your plan, a typical Alaska Inside Passage Cruise spends the first day cruising the famed Inside .Passage, a narrow waterway nestled between towering mountains, waterfront communities, and the Pacific Ocean.

Alaska Glacier Cruses.

Alaska Glacier Cruises are also known as Gulf of Alaska Cruises.Every cruise line has a different name for it, but they all mean the same thing —they are cruises that sail one-way through the Gulf of Alaska where you'll find the greatest number of glaciers(冰川), mountains, wildlife and scenery.

Unlike an Alaska Inside Passage Cruise, an Alaska Glacier Cruise does not do a U—turn back to the; departure port.Alaska Glacier cruises are one way journey that sail from.North to South (Southbound Glacier Cruises) or South to North (Northbound Glacier Cruises).These routes allow you to spend more days in Alaska ports or National Glacier Parks as there are fewer days at sea compared to other cruises.If you only have a week and want wonderful glacier viewing and time on land, this is your best choice for an Alaska Cruise Vacation.

Regent Home Alaska Cruises

For a close and personal contact with the Great White North, step aboard the All-inclusive, 700-guest Seven Seas Mariner.You can watch seabirds perform beautiful dances or a group of playful whales swim by as you're eating breakfast in your private room. 

小题1:What is "Inside Passage" according to the text? 

A.It's the name of a typical cruise ship.

B.It's a popular hiking route in Alaska.

C.It's the name of a famous tourist company.

D.It's a body of water with beautiful scenery.小题2:If you are interested in sightseeing on foot, which cruise might be a better choice than others?

A.Alaska Inside Passage Cruises.

B.Gulf of Alaska Cruises.

C.Regent Home Alaska Cruises.

D.None of the above.小题3:Which of the following cruises repeat its routes?

A.Alaska Inside Passage Cruises.

B.Southbound Glacier Cruises.

C.Northbound Glacier Cruises.

D.Seven Seas Mariner.小题4:What's the purpose of this passage?

A.To explore the natural beauty of Alaska.

B.To introduce the ways of traveling in Alaska.

C.To attract tourists to cruise vacations in Alaska.

D.To offer advice to people traveling in Alaska.