语法练习

1.DNA, ___, is found in the cell nucleus in the form of very long and thin molecules consisting of two spiral strands.

A.inherits material
B.is inheritance material
C.material is inherited
D.the material of inheritance

2.Potential dehydration is ___ that a land animal faces.

A.the often greatest hazard
B.the greatest often hazard
C.often the greatest hazard
D.often the hazard greatest

3.Before every presidential election in the United States, the statisticians try to guess the proportion of the population that ___ for each candidate.

A.are voted
B.voting
C.to be voted
D.will vote

4.Although thunder and lightning are produced at the same time, light waves travel faster ___, so we see the lightning before we hear the thunder.

A.than sound waves do
B.than sound waves are
C.do sound waves
D.sound waves

5.All the committee members said the lecture was ___ a second time.

A.worth to listen
B.worth being listened to
C.worth listening to
D.worth to listen to

答案详解

1.[D]【解析】the material of inheritance为名词词组，作同位语，解释限定主语。

2.[C]【解析】副词often须紧跟在系动词is之后，形容词最高级必须在名词hazard之前。

3.[D]【解析】在that引导的定语从句中，逻辑主语是the proportion of the population,谓语动词应用主动形式。用将来时表示对将来的推测。

4.[A]【解析】比较级中所比较的两个事物是对等的平行关系，应保持语法上的一致和语义上的对等。than后完整的形式应该是than sound waves travel，为了简练，用do代替travel。

5.[C]【解析】be worth(doing) something意为“值得某物，值得做某事”，相当于be worthy of。