简要回答下列问题

根据短文内容选择正确答案。

If you plan to take your pet on a trip, prepare ahead of time(提前). At least two weeks before you leave, take your pet to a vet. See if he or she is fit for travel and ask if he or she should have any medicine before leaving. The vet may suggest(建议) certain pills for sickness or for calming the pet.

      Some states or foreign countries have health laws that say animals must have certain injections(注射)before they can be allowed(允许) to enter. Your vet may have this information. You can also get help on the United States and Canadian laws from a book published by the Department of Agriculture which some libraries have. For information on foreign countries,  check with their consulates (领事馆).You can also ask the airlines on which you are travelling.

      Find out if the places where you plan to stay allow pets because many do not.

      If you are going by plane or train, ask if pets are allowed. If they are, ask where they will be kept and who will care for them. The big bus lines in this country do not allow pets.

      Choose your pet's box carefully. Plastic boxes are better than cardboard or wooden ones because they can't be chewed(嚼碎).

      If going by plane or train during warm weather, try to go in the cooler early morning or evening hours. Also try to avoid (避免)very cold winter weather because pets often suffer from cold. Even in your own car, be careful. Do not leave the animal inside with the windows closed because the car may become too hot or too cold.