【简答题】—The sea is very rough today. —Yes, I‘ve never seen _______ before. B.such rough sea C.such a rough sea D.so rough sea E.that rough sea
【多选题】调制解调器的组成包括( )。
E.
解析:调制解调器是为数据通信的数字信号在具有有限带宽的模拟信道上进行远距离传输而设计的,它一般由基带处理、调制解调、信号放大和滤波、均衡等几部分组成。调制是将数字信号与音频载波组合,产生适合于电话线上传输的音频信号(模拟信号),解调是从音频信号中恢复出数字信号。调制解调器一般分为外置式、内置式和PC卡式三种。
【简答题】very rough estimate选择It __________ according to where you live, and this is a very rough estimate [A] shifts [B] converts [C] modifies [D] varies
【多选题】有关变构酶的叙述正确的是
D.
酶从一种构象转变为另一种构象时,酶活性发生改变
【简答题】They stopped (search) ______ for the missing plane as the weather was very rough.