4 It is very dark. I can't see anything, 5 We aren't very rich. We can't buy that boat.6 Jennifer isn't very strong.She can't carry that suitcase7. This skirt is very small. Mary can't wear it.8 It's windy. We can't sail.9 The hillic vorbi ​

advantages:

-you may meet a lot of interesting and kind people

-it should be very poor to travell like that

-I think that it`s more comfortable than in the long-distance buses

disadvanteges:

-you may meet a very cruel or person or just a murderer or somebody like him

-it should be very poor to travell like that but I prefer to pay money and to travell with some comfort in a train or in a plane

-I suppose that if during your travelling something would break (for example,a car) nobody will help you but if you have  ordered a ticket in a company which deals with travellings, you may hope for help or to demand your money back