若宇航员在月球表面附近自高h处以初速度v₀水平抛出一个小球，测出小球的水平射程为L．已知月球半径为R，万有引力常量为G．则下列说法正确的是（　　）

A．月球表面的重力加速度g月=

B．月球的质量m月=

C．月球的第一宇宙速度v=

D．月球的平均密度ρ=

Web browser is simply a terminal emulator, designed to display text on a screen. The two essential differences between an ordinary terminal emulator and a Web browser are that the browser knows how to deal with (71) , and that it has a mechanism for (72) graphical files. Display text, display graphics, and (73) hypefiinks, there’s 99 percent of the (74) value. That’s not to say that the manufacturers didn’t go all-out to attach a hyperactive efflorescence of useless capabilities onto their browsers. Remember when media channels in the browser were a big deal, instead of the clutter you can’t wait to delete from your favorites of bookmarks menu Remember when client-side Java applets were supposed to become the preferred (75) for application development Remember frames and all their nasty side effects

A．direct

B．navigate

C．indicate

D．go-on