用before,after,when,though,if,because,so that完成以下句子。 ________ you pay for the goods, you'd better check it carefully. You need to look at the price carefully ________ you are shopping. ________ I walked for a whole day, I was really tired. ________he answered my question, I was still confused. ________ you pay with credit card, you can get a 5% discount. He leaves the door open ________ his dog can enter by herself. I couldn't feel anger against him ________ I liked him so much.