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單項(xiàng)選擇題

白化病的頭發(fā)是白的,因?yàn)榛颊叩幕驂牧?所以從酪氨酸轉(zhuǎn)變成黑色素的這個(gè)過(guò)程中的（）沒(méi)有,即使吃何首烏還是不能讓頭發(fā)變黑

A.DNA
B.RNA
C.維生素
D.酶

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單項(xiàng)選擇題

－－－Goodbye, Peter, remember me to your prents.－－－_______.It’s very kind of you to sy so.B．

Thnk. ---Goodbye, Peter, remember me to your prents. ---_______.It’s very kind of you to sy so. B．Thnks, I will. C．Youre so kind. D．Thnks, wht good ide.A．It’s very kind of you to say so．B．Thanks, I will．C．You are so kinD．Thanks, what a good ideA．

問(wèn)答題

Thank you, Sir. It’s so kind of you to give way to this senior gentleman.

答案：先生,非常感謝您讓這位老先生先走。

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