有丝分裂向减数分裂转变的不可逆的时期是()
A、G1
B、S
C、G2
D、M
参考答案:B
Early to bed and early to rise ________ a man healthy, wealthy and wise.[ ]
A.make
B.makes
C.have made
D.will make
紧固组装螺栓时,各螺栓须()拧紧,不得偏压。