患儿,7岁,下颌右侧第一乳磨牙远中邻面深龋,穿髓,经根管治疗后,应采取的治疗措施是()
A.金属全冠
B.金属嵌体
C.树脂嵌体
D.牙体充填术
E.塑料全冠
参考答案:D
下列各多项式能用完全平方公式因式分解的个数有( )
①x2-10x+16
②-a2+8a-16
③m2-12m-36
④-p2-18p-81.
A.1个
B.2个
C.3个
D.4个
They can find whatever they need in the supermarket, ______ is always busy on Sundays.
A.which
B.when
C.where
D.who