题目

In the United States, it is not customary（习惯的）to telephone someone very early in the morning. If you telephone him early in the morning, __________ he is shaving or having breakfast, the __________ of the call shows that the matter is very important and __________ immediate attention. The same meaning _________with telephone calls made after 11:00 pm. If someone __________ a call during sleeping hours, he considers it a matter of life and __________.The time chosen for the call communicates its importance.In __________ life, time plays a very important part. In the U.S., ____________一架飞机水平地匀速飞行.从飞机上每隔1秒钟释放一个铁球,先后共释放4个.若不计空气阻力,则四个球： (     )A．在空中任何时刻总是排成抛物线;它们的落地点是等间距的.B．在空中任何时刻总是排成抛物线;它们的落地点是不等间距的.C．在空中任何时刻总在飞机正下方排成坚直的直线;它们的落地点是等间距的.D．在空中任何时刻总在飞机正下方排成竖直的直线;它们在空中等间距排列.