一个四棱锥和一个三棱锥恰好可以拼接成一个三棱柱.这个四棱锥的底面为正方形,且底面边长与各侧棱长相等,这个三棱锥的底面边长与各侧棱长也都相等.设四棱锥、三棱锥、三棱柱的高分别为,,,则( )
You’d better _______his name, address and telephone number before you forget them.
I’d like to know _________ Chinese.
—Do you mean that we have lost our way? —_________!
— Jenny, it seemed that your partner didn’t dance well. — Oh, _____Three boys to choose from and I picked the stupid one.
Jeff is hard-working. He seldom, _____, comes to work late and leaves off early.