复速级为什么能提高轮周效率？

为区分起见，两相邻零件的剖面线应方向（），而同一零件在各剖视图中，其剖面线的方向应（），间隔应（）。

天气热极了，小利在家写作业，汗流不止，抬头看了看挂在墙上的寒暑表如图所示，当时室温为_________。于是她打开电风扇，立刻感到凉快多了，这时她又看了看寒暑表，发现示数_________(选填“升高”、“不变”或“降低”)。这是因为打开电风扇加快了_________，从而加快了_________，而没有改变_________。

关于业主对共有部分享有共有和共同管理权利的说法，正确的是( )。

A．业主享有权利、承担义务，不履行义务的前提是放弃权利

B．业主依据相关法律、法规等的规定行使占有、使用、收益或者处分的权利

C．业主可以根据需要调整建设规划，改变绿地、道路、停车位等布局

D．业主专有部分出租时，可以一并转让共有权和共同管理权

When a disease of epidemic proportions threatens the public, scientists immediately get to work, trying to locate the source of affliction and find ways to combat. Vaccination is one of the effective ways to protect the (1) population of a region or country which may be (2) grave risk. The process of vaccination allows the patient’s body to (3) immunity to the virus or disease so that, if it is encountered, one can fight it (4) naturally. To accomplish this, a small weak or dead (5) of the disease is actually injected into the patient in a controlled environment, (6) his body’s immune system can learn to fight the invader (7) . Information (8) how to penetrate the disease’s defenses is (9) to all elements of the patient’s immune system in a process that occurs naturally, in which genetic information is passed from cell to cell. This makes sure that (10) the patient later come into contact with the real problem, his body is well equipped and trained to (11) with it, having already done so before.

There are, however, dangers (12) in the process. (13) , even the weakened version of the disease contained in the vaccine proves (14) much for the body to handle, resulting in the immune system (15) , and, therefore, the patient’s death. Such is the case of the smallpox vaccine, (16) to eradicate the smallpox epidemic that nearly (17) the whole Native American population and killed massive numbers of settlers. (18) 1 in 10,000 people who receive the vaccine (19) the smallpox disease from the vaccine itself and dies from it. Consequently, the process, which is truly a (20) , may indeed hide some hidden curses.

10（）

A.would

B.should

C.if only

D.even if

条田