在Rt△ABC中,若∠C=90°,tanA·tan20°=1,则∠A=( )。
70°
—You were driving at 100 km an hour, sir.
—But officer, I ________. My car can’t go more than 80.
A.may not have to
B.couldn’t have been
C.wouldn’t like to
D.needn’t to be
供配电系统中,敷设于同一金属线槽内的导体总截面(包括保护层),不应超过线槽内截面的(),导体根数不宜超过()根。
A.20%,20
B.20%,30
C.40%,20
D.40%,30