Выберите правильный вариант:
1) She made a mistake... she was careless.
a) because
b) because of
2) She made a mistake... being careless.
a) because
b) because of
3) We couldn't come on time... the rain.
a) because
b) because of
4) We couldn't come on time... the rain had not stopped.
a) because
b) because of