问答题 2. Listen again and fill in the blanks to complete the following sentences. 1) Chopsticks only became two sticks of  _____________________ in _______________________Dynasty. 2) The Grand Canal served as the main ____________________ between northern and southern China and was essential for the transport of _________________________ and other produce to Beijing. 3) “筷” is a ____________________ compound with a phonetic _____________________ meaning “________________________”and a semantic part meaning “ _________________________________”. 4) The English word "chopstick" may have derived from Chinese ______________________, a pidgin in which “ ______________________” meant “_________________________”. So “fast” became chop and “_________________________” became _________________________________  . 5) The birth of chopsticks ________________________________ those days when our Chinese ancestors had to use ___________________________ to eat, so they mark _______________________ in food culture.

不定项选择 不孕的医学定义为两年以上未采取任何避孕措施，性生活正常而没有成功妊娠

判断题 仅有一个结点的图称为零图 正确 错误