He wants to learn on/at/to/by/of/about other countries.

He wants to learn about other countries

He wants to learn other countries. но he wants to learn something about other countries.

Kolya: let's have a snack! kostya: i'd rather have a meal kolya: let's go to the cafe kostya: it's fine with me! at the cafe kolya: is this table reserved? waiter: yes, it is kostya: show us the  menu,please waiter: can i take your order? kolya: fruit salad and a glass of milk for me kostya: i'll have the same waiter: how about the sweet? kostya: no sweet, thanks. just two coffees kolya: may i have the bill, please? kolya: how much do i owe you? waiter: 2500 rubles(рублей) kolya: keep the change

1)mum has bought some pears                                                                               2)jane has seen the statue ofliberty                                                                     3)my friends have swum over  the lake                                                                   4)it is today and rick has drunk a lot   of cold water