不同法的形式具有不同的效力等级，下列各项中，效力低于地方性法规的是（）。 A.宪法

右下肺动脉的宽度正常不超过（）

A.16mm

B.1.5mm

C.15cm

D.15mm

E.20mm

多发性骨髓瘤最有诊断意义的是 （）

A.原因不明的贫血

B.肾功能障碍

C.肋骨的病理性骨折

D.血清球蛋白增高

E.骨髓检查发现>30%的异常浆细胞

下列哪项不是间接固位体的主要作用（）

A．防止游离端基托向脱位和侧向移位

B．减少因义齿沿支点线转动而造成对基牙的损害

C．用于上颌义齿有对抗义齿游离端重力的作用

D．有分散力减轻基牙负担的作用

E．连接义齿各部分成一整体

The people who lives in the far North are called Eskimos(爱斯基摩托车人). In the world of ice and snow it is (21) to grow plants for food. The Eskimos must hunt and fish during the whole year to (22) themselves and their families with food.

In winter, they hunt the seal(海豹) (23) the polar(极地的) bear. When they hunt the seal, they (24) a hole in the ice and try to (25) the seal when it comes up to breathe.

In summer, the Eskimos hunt (26) animals, and they also hunt birds and catch fish.

(27) that is useful is saved. The Eskimos use the meat from animals for food. They melt(融化) the fat from their bodies and use the (28) as fuel(燃料). They make tools out of animals bones. The skin and furs of animals are used for making clothing.

If an Eskimo is (29) lucky, he may kill a whale(鲤鱼), (30) a dead whale may wash up on the shore near his house. The whale is an especially useful animal, because it gives a great (31) of oil.

There is (32) wood at all where the Eskimos live. Eskimos (33) all their wood from the sea. Sometimes floating wood from places farther south washes up on the shore.

Most Eskimo houses are (34) of stones. Instead of a door, there is a long, low tunnel (地道) (35) into the house. People have to crawl(爬) through the tunnel in order to enter the house.

29（）

A．much

B．often

C．not

D．very

简述生物修复三原则。