将一要导线均匀拉长为原长的2倍,则它的阻值为原阻值的()倍。
A、2;
B、1;
C、4。
参考答案:C
—Mother, I climbed up to that tall tree and picked this big apple.
—Jesus! You______ down and hurt yourself.
A.might have fallen
B.might fall
C.must have fallen
D.must fall
女孩的尿路感染最常见病原菌是()
A.大肠杆菌
B.变形杆菌
C.白色葡萄球菌
D.克雷伯杆菌
E.金黄色葡萄球菌