另两个为胸腺嘧啶和胞嘧啶, 即称为嘧啶的单环结构.The other two, thymine and cytosine, are single ring structures called pyrimidines.直到不久以前,人们对胸腺的功能尚不明了.The function of the thymus was unknown until relatively recently.动物的免疫系统由两个主要部分组成,即胸腺和骨髓系统.I...
The rescuers tunnelled their way ( in ) to the pot - holers.救援人员挖地道通向那些探察洞穴的人.They tunnelled along under the walls and up into the woods beyond.他们在围墙下面挖地道通向远处的树林.The rebels tunnelled out of a maximum security jail...叛乱者挖...
Angela stared pensively out of the window.安杰拉忧郁地望着窗外。Alice gazed pensively through the wet glass...艾丽斯透过湿漉漉的玻璃神情忧郁地凝视着窗外。Alice gazed pensively through the wet glass.艾丽斯透过湿漉漉的玻璃神情忧郁地凝视着窗外。Garton pensively stirred the hotc...
The school has been in continual use since 1883.自1883年以来，该校从未停办过。They felt continual pressure to perform well.他们不断感受到压力，促使他们好好表演。She finds the continual confrontation very wearing.她发现持续的对峙让人精疲力竭。...