English question - urgent

1. We usually need to bend ourselves to get into the taxi, so it is 'in' the taxi. For train, plane and bus, we just need to walk up into it. (This is provided by my English teacher)
2. 'in' bed indicates that you are going to be asleep. 'on' bed just simply indicates that you are on the bed. Another way to explain is to indicate your location.

(I hope my explanations could help!)

Prepositions of Place: at, in, onIn general, we use:at for a POINTin for an ENCLOSED SPACEon for a SURFACE
Please check it out yourself at the following website:
http://www.englishclub.com/grammar/prepositions-at-in-on-place.htm

首先回答第 2 題，答案係 "in bed" 同 "on THE bed"，記着係 on THE bed 中間須要有個 "THE"字，而"in bed" 中間不用加 THE。
前者 in bed 係指在床上睡覺或蓋上被睡覺。
後者 on the bed 係指趟在床上或某些東西放在床上，例如 There is a pillow on the bed.有一枕頭放在床上。
總括 in bed 多數指睡覺或蓋上被睡覺，on the bed 多數指趟在床上或某些東西放在床上。

第 1 題，有時介詞未必可每一個解釋得到，及可變化的，只可記着以下給你一些例子：
in a car，on a bus
in a taxi，on a train
in a helicopter， on a plane
in a boat， on a ship
in a lift， on a bicycle, on a motorbike
in the newspaper， on a horse
in the sky， on the radio, on television, on the internet
in XXX Street， on the way