— My eyesight is getting worse these days. I'd like to have my eyes ______.
— Perhaps you should consider ______ the time on the computer.
A:checked; to reduce
B:to check; reducing
C:checked; reducing
D:checking; to check
某电热水器中装有质量为40kg的水,通电后该热水器中水的温度从15℃升高到65℃,这些水吸收的热量是____ J。 =4.2×103J/(kg·℃)
小明站在匀速直线行驶的汽车上,以车厢为参照物,小明是____ 的;若汽车突然加速,小明将向____ 倾(选填“前”或“后”).
① f(x)=p⋅qx ;② f(x)=px2+qx+1 ;③ f(x)=x(x−q)2+p .(以上三式中、 p,q 均为常数,且 q>1 )
下列关于无脊椎动物的叙述,不正确的是( )