置于204℃±5℃的干燥箱内5min后，安全绳不出现熔融、焦化现象。
参考答案：对
改错。
( )1. How does you brother go to school? __________
A B C D
( )2. —How often is it from your home?
—Two miles. __________
( )3. Do you take your bike to work? __________
( )4. He often walks to school on foot. __________
( )5. It takes her half an hour clean her room. __________
信用证是一种银行开立的无条件承诺付款的书面文件。( )
