She’s having a lot of trouble with the new computer, but she doesn’t know whom to _______.

Youcan’t borrow books from the school library ______ you get your student card

In 1831, Faraday discovered that electricity moves through a wire ________ a magnet（磁铁） is moved near the wire

My mother often_______ after supper with my sister .

ng that the students were having anevening class, the teacher left the classroom, _____.