2. 译为原因状语从句

* A cat, whose eyes can take in many more rays of light than our eyes, can see clearly in the night.

由于猫的眼睛能比我们人的眼睛吸收更多的光线，所以猫在黑夜也能看得很清楚。 

* Transformers cannot operate by direct current, which would burn out the wires in the transformers.

变压器不能使用直流电，因为直流电会烧坏其中的导线。

* A deep wound, where the supply of blood and oxygen has been cut off, is the

perfect place for certain kinds of bacteria to grow.

深的伤ロ是某些种类的细菌孽生的理想场所，因为那里的供血和供氧被切断。

3. 译为条件状语从句

* An electric current begins to flow through a coil, which is connected across a charged condenser.

如果线圈同充电的电容器相连接，电流就开始流过线圏。

* Most children who developed meningitis, an infection of the brain's envelope, died, or suffered brain damage.

儿童如果患了脑膜炎（脑膜感染）多数会死亡或者脑子受损伤。

4. 译为其他状语从句

Electronic computers, which have many advantages, cannot carry out creative work and replace man.

虽然电子计算机有很多优点，但他们不能进行创造性的工作，也代替不了人。