在近量程下，应当选择______。 A．宽脉冲和低重复频率。 B．宽脉冲和高重复频率。 C．窄脉冲和高重复频率。

Each student has to ______ a composition once a week．

A．hand out

B．hand in

C．hand down

D．hand over

She once again went through her composition carefully to all spellingmistakes)

A) withdraw

B) diminish

C) abandon

D) eliminate

Each student has to ______ a composition once a week．

A．hand out

B．hand in

C．hand down

D．hand over

Philip is good at writing．Last week his composition was once again ______ for special praise．

菲利普很擅长写作。上周他的作文又被挑选出来予以特别奖励。

Luckily enough, we have finished (write) __________ the composition in a quarter of an hour.

Once we receive your order, we will ______ goods to your in twenty-four hours.

A．distribute

B．transfer

C．deliver

D．convey

Once we are in charge of love, it can be with us for the rest of our lives.()

As it is very ______, we must decide at once what to do.

A．eager

B．anxious

C．urgent

D．tense

Once he (arrive) ______ , we will start.