在“探究求合力的方法”的实验中,把橡皮条一端固定于P点,另一端通过细绳套连接两只弹簧秤,并使该端拉至O点,测得PO长为L,如图所示.则实验中( )
A:选取的细绳套适当长一些
B:只需要记录弹簧秤的读数
C:两根细绳套间的夹角尽可能大些
D:改用一只弹簧秤拉橡皮条时,只需使橡皮条的长度仍为L
⑴Are these your shoes? ____ A. It's a T-shirt.
⑵What are these ? ____ B. They are keys.
⑶What is this? ____ C. Yes, they are.
⑷Is this your blue shirt? ____ D. It's Jenny's.
⑸Whose sweater is this?____ E. No, it's not.
纸的主要原料是____,用旧棉布、____、____等也可以做纸
两伊战争结束后,伊拉克领导人萨达姆的侵略目标是( )