五、閱讀測驗        Do you go abroad by plane a lot? If so, you may be familiar with jet lag. What is jet lag? It is the confused and tired feeling you may get after traveling between time zones, usually on an airliner. This is becoming a common problem nowadays because more and more people are taking frequent flights. Among them, 49 percent think jet lag is just something annoying, while 45 percent think it is a real problem. It disrupts our internal biological clock and may cause digestive, sleeping, and energy-related problems.        What is jet? Jet refers to a fast airplane with a jet engine. And what is lag? Lag means delay. Therefore, jet lag is the delay of your body caused by taking a jet airliner across time zones. To be specific, it happens when you go on a west-to-east journey between time zones because it makes us late compared to the time in our destination. Ourbodies struggle to catch up with the new time, because it is always harder to speed up than to slow down.        If you travel from east to west, however, your time will be faster than the local time. As mentioned before, this is relatively easy to conquer. The seriousness of jet lag will arise if we travel across multiple time zones. On the contrary, if we go north or south, we won't notice any difference, since there is usually no time zone change. Next time when you take a really long flight east, brace yourself for jet lag.
【題組】46. What may jet lag cause you to feel?
(A) High.
(B) Tiredness.
(C) Easiness.
(D) Energy.