by twos

As I took the stairs by twos to the second floor, I noticed that the door to the day care was propped open.

大踏步迈上楼梯，来到二层，我注意到日托中心的门是开的。

They left by twos and threes.

他们三三两两地离开.

Line up by twos.

两个两个排队。

People came by twos and threes.

人们三三两两地来了.

The came to school by twos and threes.

他们三两成群地来到了学校。

We went to the station by twos and threes.

我们三三两两地走向车站.

They came in by twos and threes.

他们三三两两地进来.

They began to leave the auditorium by ones and twos.

他们开始三三两两地离开了礼堂.

They came home from church by twos and threes.

他们三三两两地从教堂回来.

He could count by twos.

他已经学会数奇偶数了.

They walked into the meeting room by twos and threes.

他们三三两两地走进会议室.

Soon the guests by twos and threes.

不久客人就三三两两地到达了.

These primers were combined by twos in order to establish the multiplex PCR and nest PCR system used to sex rabbit embryo, and then, the system were chosen and optimized.

根据这些引物组合建立了兔早期胚胎性别鉴定的双重和巢式PCR反应体系。

Franklin could ( 1) count by twos and ( 2) tie his shoes.

富兰克林学会了数奇偶数，他还学会了自己系鞋带。

We went out by twos.

我们两个两个走出去.

Franklin could count by twos, and tie his shoes.

富兰克林已经学会奇偶数了, 他还学会了自己系鞋带.

The boys come in toghter and go out by twos and threes.

男孩子们一起进来,又三三两两的出去了.

The students are coming into the classroom by twos and threes.

学生们正三三两两地走进教室.

But though the other boarders kept coming in by ones, twos, and threes, and going to bed, yet no sign of my harpooneer.

但是，虽然其他的住客已经一个，两个，三个不断的走进来.睡觉去了，我那个标枪手却仍然不见踪影。

The children went on an outing hand in hand by twos.

孩子们两两地手拉着手出去郊游.

These findings often were by twos and threes found in same patient.

这些X线征象往往两种或两种以上并存于同一患者之中。

They came to see me by twos and threes.

他们三三两两地来看我.