Fill the gaps in these magazine horoscopes​

Do (Present Simple) animals have (Present Simple) any unexplained powers we are (Present Simple) unaware of? For many years pet owners and scientists have reported (Present Perfect) examples of unusual behaviour in animals. They say (Present Simple) that pets can (Present Simple) anticipate (Infinitive) their owners leaving for trips or returning home. These animals somehow know (Present Simple) when they are going (Present Cont) to be fed (Infinitive) or taken for a walk. Does (Present Simple) this mean (Present Simple) anything or is (Present Simple) it just a coincidence? Maybe it has (Present Simple) nothing to do (Infinitive) with psychic powers, maybe pets just understand (Present Simple) enough language to get (Infinitive) the message? Surprisingly, little research has been done (Present Perfect) on these phenomena.

1)  During this period the track structure has been substantially improved. One of the greatest improvements was the elimination of rail joints. In order to reduce the number of joints the rails are welded into continuous lengths.These continuous or long welded rails have greater strength and provide a smoother running of trains at far greater speeds.
2) Another improvement which has made it possible to increase speeds on railways is the use of concrete sleepers. Thus in some countries , concrete sleepers have replaced wooden ones on heavily used main lines because of their advantages.
Concrete sleepers have a longer life and a far greater weight than those made of wood. The greater weight of concrete sleepers provides the greater stability of track.
It is this factor which has greatly contributed to increased speeds.

ответ взял прямо из текста. Насколько я помню, так надо делать в подобных заданиях.