六氟化硫介质具有优越的()性能。
A.绝缘;
B.耐腐蚀;
C.防潮;
D.灭弧。
参考答案:A, D
__________ sleep every night is important for teenagers. _________, loss of sleep can make you feel tired, and even cause you to put on weight.
A.A good amount of; As a matter of fact
B.A good number of; In truth
C.A large amount of; As matter of fact
D.Plenty of; In a fact
我国的动物种类多种多样,据统计,我国的脊椎动物有( )
A.2800种
B.6300种
C.360种
D.1600种