问题
填空题
根据音标拼写单词，使句子意思完整正确
1. He [spend]_________ too much time playing with them.
2. It’s my first time to ________ [ju:z] the computer.
3. I usually go to bed at 9:00 but I can’t go to _______ [sli:p] at once
4. He is busy _______
organizing the activities
5. They are good _______ 
答案
1. spends 2. use 3. sleep 4. practising 5. swimmers
的关系图线，如图所示。从图象中可以看出，作用在物体上的恒力F=____________N。当物体的质量为2.5kg时，它的加速度为____________m/s2。 