考博考试

【单选题】The author tells us that
A．whether a liquid-fuel or a solid-fuel rocket is better depends on the purpose
B．neither type is superior
C．forty years ago, large solid-fuel rockets with solid fuels as powerful as liquid fuels were made
D．the thrust can be made to vary by adjusting the direction of the pump
网考网参考答案：A
网考网解析：
文中作者首先提到一些外行的问题，两种火箭哪个更好，作者认为两者have their own advantages，随后列举了在military和manned space flight方面各自的用途，可以判断作者想告诉人们两种火箭的优劣在于其用途，选项A正确。 document.getElementById("warp").style.display="none"; document.getElementById("content").style.display="block"; 查看试题解析出处>>