A: kπ2 ﹣ π12 , kπ2 + 5π12 (k∈Z)
B:( kπ2 ﹣ π12 , kπ2 + 5π12 )(k∈Z)
C:(kπ+ π6 ,kπ+ 2π3 )(k∈Z)
D:kπ﹣ π12 ,kπ+ 5π12 (k∈Z)
取一只小塑料袋(重力忽略不计),袋内装满水,用细线把袋口扎紧(要求袋内不留空气),然后用弹簧测力计将它吊起,称出水所受的重力.将这袋水逐渐浸入水中,弹簧测力计读数逐渐变小,表明水袋所受浮力的大小随排开水的体积增大而 ____当水袋全部浸没水中时,弹簧测力计的读数为零,说明这时水袋所受浮力等于 ____
简述光合作用意义
Though you failed this time, don't give up ____ (study) . You still have a lot of chances.