质点做简谐运动的周期为T，则质点在振动过程中相位增加π/2所需要的时间

科学和技术的不同 黄历上说忌出行是什么意思 皇历里面“忌”栏中有时写“诸事不宜”是什么意思? 黄历上的宜和忌分别是什么意思宜；下面的什么事是都能做是吗?忌；下面的什么事最好不要做是吗? 老黄历上说的忌赴任是什么意思 you are/were supposed to have本应该用 were 还是arebe supposed to have done 翻译成本应该不是问be supposed to do这个我懂 正确形式填空：Please keep them ____(close).请说明原因,急 Tell TOM to open the window(改为否定句） Tell Tom ( )( ) open the window 正确形式填空：Please keep them ____(close).请说明原因 nothing in the world Without You 什么意思? I need nothing Except.U谢谢帮忙翻译下 电子科学与技术与电子信息科学与技术哟什么区别啊? Where your sister (teach)English?My grandpa (come)tonight.Tell him (not look)out of the window.He finished(read)the book and passed it to her.--It's very important (learn)all the subjects well.--There's a watch(lie)on the ground,--It took mr two hour be supposed to do sth与should have done sth 有什么区别? Tell Tom not to look out of the window,will you?或Tell Tom not to look out of the window,will he?哪个对? I tell my brother ( )(not look)out of the window in class.填什么 1What time___ we ___(meet) tomorrow 2Tell him ____(not look) out of the window “馀事勿取”是什么意思 I prefer to play football.I prefer playing football. i prefer (playing) football.有prefer doing的形式吗 loveing the sky without wings 斜面和滑轮都是杠杆的变形吗 定滑轮是一个变形的___杠杆 滑轮是变形的杠杆,所以使用滑轮不一定省力 得到正解悬赏30 My english name is Selebi! I like it! 有首英文歌 开头是 my heart is a paradise... 求歌名是最近在电台里听到的 be good at sth与be good at doing sth的区别,另外be good whth sb是什么意思? 漂亮的什么填词语 什么得漂亮,填一个词语 用所给词的适当形式填空 ＿(not look)out of the window in class! 用所给词的适当形式填空:We shouid ( )[not,look] out of the window in class. 请问英语怎么翻译?