Improve the highlighted part of the sentence given below.
You cannot forbid $him\, leaving.$

Improve the highlighted part of the sentence given below.
As she was suffering from high fever,she could not $face$ the examination.

Improve the highlighted part of the sentence given below:
He could not $look$ anything in the dark room.

Improve the highlighted part of the sentence given below.
His father won't be able to leave for Varanasi $until\, they\, have\, arrived.$

Improve the highlighted part of the sentence given below:
The reason $why\, he\, wrote\, the\, letter\, was\, because$ he could not contact him over the phone.

Improve the highlighted part of the sentence given below:
$I$ would have waited for you at the station if $I$ $knew$ that you would come.