工程师说钚可能会开始从遭腐蚀的潜艇往外渗透。Engineers said that plutonium could begin seeping from the corroded sub.危险的辐射物从钚放散出来.Dangerous emissions radiate from plutonium.钚也可以用来制成核武器.The plutonium also could be used, however, to make nuclear...
植物的肺就是其叶片上微细的气孔。A plant's lungs are the microscopic pores in its leaves.在干旱的条件下, 叶子的膨压减少而气孔关闭.Under conditions of water stress, leaf turgor decreases and stomata close.他使橡胶塞牢固地塞进盖上的排气孔.He presses the rubber stopper ...