水的比热容比煤油的大，隔着石棉网同时加热规格相同、分别装上质量和初温都相同的煤油和水的试管，至管内液体升温到40℃，这个过程中（   ）

    Many people today like reading stories about UFO.Many people in different countries are studying the UFO.

    There are some different saying for UFO.Among those sayings,the most popular one for UFO is that UFOs are strange creatures(生物) to the earth from other stars.We can call them aliens.

    UFO scientists and many people believed this saying.Some people said that they saw a few UFOs landing on the earth.They seemed to be objects rather like big plates.Some people said that they saw some strange visitors coming out of the UFOs.

    Some people make mistakes when they say they have seen UFOs high in the sky.Perhaps they see a weather balloon or an uncommon plane or the light they see in the sky comes from the ground.Sometimes they see the light from the moon.

    But these are a lot of others we can't understand.It may take many years to find a clear answer and then people will give UFO another name.

如图图所示是列车上常用的手推车，车内货物均匀摆放，车前行时，需经过障碍物，当车的前轮遇到障碍物A时，售货员向下按扶把，这时手推车可视为杠杆，若手推车和货物总重200N，动力臂和阻力臂之比为2∶3，此时手推车是____（填“省力”或“费力”）杠杆，售货员作用在扶把上的动力为____ N。当后轮遇到障碍物A时，售货员竖直向上提扶把，这时____（填“A”、“B”或“C”）为支点。

下列划线字的注音完全正确的一项是（  ）。