荧光抗体直接法的最大特点是
A.特异性差,敏感性高
B.特异性高,方法简便快捷,敏感性高
C.特异性高,敏感性高
D.特异性高,方法简便快捷,敏感性较差
E.操作复杂
参考答案:D
Not only ________learn a foreign language, but also ______ master it well.
A.must we ; we must
B.must we ; must we
C.we must ;’ we must
D.we must ; must we
烧结时出现的产品开裂有()、高温开裂和冷却开裂几种。